81588630840 has 32 divisors (see below), whose sum is σ = 244765892880. Its totient is φ = 21756968192.

The previous prime is 81588630833. The next prime is 81588630931. The reversal of 81588630840 is 4803688518.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 339952509 + ... + 339952748.

Almost surely, 2^81588630840 is an apocalyptic number.

It is an amenable number.

81588630840 is an abundant number, since it is smaller than the sum of its proper divisors (163177262040).

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

81588630840 is a wasteful number, since it uses less digits than its factorization.

81588630840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 679905271 (or 679905267 counting only the distinct ones).

The product of its (nonzero) digits is 1474560, while the sum is 51.

The spelling of 81588630840 in words is "eighty-one billion, five hundred eighty-eight million, six hundred thirty thousand, eight hundred forty".