81051300 has 144 divisors (see below), whose sum is σ = 284356800. Its totient is φ = 19641600.

The previous prime is 81051281. The next prime is 81051331. The reversal of 81051300 is 315018.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 28336 + ... + 31064.

It is an arithmetic number, because the mean of its divisors is an integer number (1974700).

Almost surely, 2^81051300 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81051300, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (142178400).

81051300 is an abundant number, since it is smaller than the sum of its proper divisors (203305500).

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

81051300 is a wasteful number, since it uses less digits than its factorization.

81051300 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2763 (or 2750 counting only the distinct ones).

The product of its (nonzero) digits is 120, while the sum is 18.

The square root of 81051300 is about 9002.8495488928. The cubic root of 81051300 is about 432.7661942884.

Adding to 81051300 its reverse (315018), we get a palindrome (81366318).

The spelling of 81051300 in words is "eighty-one million, fifty-one thousand, three hundred".