81586961988 has 48 divisors (see below), whose sum is σ = 217661458560. Its totient is φ = 23300250624.

The previous prime is 81586961983. The next prime is 81586962001. The reversal of 81586961988 is 88916968518.

It is not an unprimeable number, because it can be changed into a prime (81586961983) 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, 22723 + ... + 404586.

It is an arithmetic number, because the mean of its divisors is an integer number (4534613720).

Almost surely, 2^81586961988 is an apocalyptic number.

It is an amenable number.

81586961988 is an abundant number, since it is smaller than the sum of its proper divisors (136074496572).

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

81586961988 is a wasteful number, since it uses less digits than its factorization.

81586961988 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 429596 (or 429594 counting only the distinct ones).

The product of its digits is 59719680, while the sum is 69.

The spelling of 81586961988 in words is "eighty-one billion, five hundred eighty-six million, nine hundred sixty-one thousand, nine hundred eighty-eight".