81115731210 has 32 divisors (see below), whose sum is σ = 194706081792. Its totient is φ = 21627714240.

The previous prime is 81115731197. The next prime is 81115731211. The reversal of 81115731210 is 1213751118.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is not an unprimeable number, because it can be changed into a prime (81115731211) 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, 16695 + ... + 403125.

It is an arithmetic number, because the mean of its divisors is an integer number (6084565056).

Almost surely, 2^81115731210 is an apocalyptic number.

81115731210 is an abundant number, since it is smaller than the sum of its proper divisors (113590350582).

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

81115731210 is a wasteful number, since it uses less digits than its factorization.

81115731210 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 393438.

The product of its (nonzero) digits is 1680, while the sum is 30.

The spelling of 81115731210 in words is "eighty-one billion, one hundred fifteen million, seven hundred thirty-one thousand, two hundred ten".