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81030 = 2353773
BaseRepresentation
bin10011110010000110
311010011010
4103302012
510043110
61423050
7455145
oct236206
9133133
1081030
1155974
123aa86
132ab61
142175c
1519020
hex13c86

81030 has 32 divisors (see below), whose sum is σ = 202464. Its totient is φ = 20736.

The previous prime is 81023. The next prime is 81031. The reversal of 81030 is 3018.

It is an alternating number because its digits alternate between even and odd.

It is a junction number, because it is equal to n+sod(n) for n = 80997 and 81015.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81031) by changing a digit.

81030 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1074 + ... + 1146.

It is an arithmetic number, because the mean of its divisors is an integer number (6327).

281030 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81030, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (101232).

81030 is an abundant number, since it is smaller than the sum of its proper divisors (121434).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81030 is a wasteful number, since it uses less digits than its factorization.

81030 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 120.

The product of its (nonzero) digits is 24, while the sum is 12.

The square root of 81030 is about 284.6576891637. The cubic root of 81030 is about 43.2728281150.

Subtracting from 81030 its sum of digits (12), we obtain a palindrome (81018).

Adding to 81030 its reverse (3018), we get a palindrome (84048).

The spelling of 81030 in words is "eighty-one thousand, thirty".

Divisors: 1 2 3 5 6 10 15 30 37 73 74 111 146 185 219 222 365 370 438 555 730 1095 1110 2190 2701 5402 8103 13505 16206 27010 40515 81030