81537643470 has 32 divisors (see below), whose sum is σ = 195699719808. Its totient is φ = 21742329888.

The previous prime is 81537643417. The next prime is 81537643471. The reversal of 81537643470 is 7434673518.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81537643471) 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, 731157 + ... + 835263.

It is an arithmetic number, because the mean of its divisors is an integer number (6115616244).

Almost surely, 2^81537643470 is an apocalyptic number.

81537643470 is an abundant number, since it is smaller than the sum of its proper divisors (114162076338).

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

81537643470 is a wasteful number, since it uses less digits than its factorization.

81537643470 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 130224.

The product of its (nonzero) digits is 1693440, while the sum is 48.

The spelling of 81537643470 in words is "eighty-one billion, five hundred thirty-seven million, six hundred forty-three thousand, four hundred seventy".