Search a number
-
+
81189433 = 1317379929
BaseRepresentation
bin1001101011011…
…01101000111001
312122202211222001
410311231220321
5131241030213
612020101001
72004045613
oct465555071
9178684861
1081189433
1141913906
1223234761
1313a888b0
14aad5db3
1571db1dd
hex4d6da39

81189433 has 16 divisors (see below), whose sum is σ = 95089680. Its totient is φ = 68622336.

The previous prime is 81189401. The next prime is 81189439. The reversal of 81189433 is 33498118.

It can be written as a sum of positive squares in 8 ways, for example, as 45369 + 81144064 = 213^2 + 9008^2 .

It is not a de Polignac number, because 81189433 - 25 = 81189401 is a prime.

It is a super-2 number, since 2×811894332 = 13183448061722978, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (37).

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 81189392 and 81189401.

It is not an unprimeable number, because it can be changed into a prime (81189439) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3213 + ... + 13141.

It is an arithmetic number, because the mean of its divisors is an integer number (5943105).

It is a Poulet number, since it divides 281189432-1.

Almost surely, 281189433 is an apocalyptic number.

It is an amenable number.

81189433 is a deficient number, since it is larger than the sum of its proper divisors (13900247).

81189433 is a wasteful number, since it uses less digits than its factorization.

81189433 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9996.

The product of its digits is 20736, while the sum is 37.

The square root of 81189433 is about 9010.5179096432. The cubic root of 81189433 is about 433.0119043711.

The spelling of 81189433 in words is "eighty-one million, one hundred eighty-nine thousand, four hundred thirty-three".

Divisors: 1 13 17 37 221 481 629 8177 9929 129077 168793 367373 2194309 4775849 6245341 81189433