81587634 has 16 divisors (see below), whose sum is σ = 171763680. Its totient is φ = 25764480.

The previous prime is 81587633. The next prime is 81587651. The reversal of 81587634 is 43678518.

It is not an unprimeable number, because it can be changed into a prime (81587633) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 357727 + ... + 357954.

It is an arithmetic number, because the mean of its divisors is an integer number (10735230).

Almost surely, 2^81587634 is an apocalyptic number.

81587634 is an abundant number, since it is smaller than the sum of its proper divisors (90176046).

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

81587634 is a wasteful number, since it uses less digits than its factorization.

81587634 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 715705.

The product of its digits is 161280, while the sum is 42.

The square root of 81587634 is about 9032.5873369705. The cubic root of 81587634 is about 433.7186656655.

The spelling of 81587634 in words is "eighty-one million, five hundred eighty-seven thousand, six hundred thirty-four".