81802521580 has 24 divisors (see below), whose sum is σ = 184999549392. Its totient is φ = 30204007872.

The previous prime is 81802521553. The next prime is 81802521607. The reversal of 81802521580 is 8512520818.

It is an interprime number because it is at equal distance from previous prime (81802521553) and next prime (81802521607).

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, 157312282 + ... + 157312801.

It is an arithmetic number, because the mean of its divisors is an integer number (7708314558).

Almost surely, 2^81802521580 is an apocalyptic number.

It is an amenable number.

81802521580 is an abundant number, since it is smaller than the sum of its proper divisors (103197027812).

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

81802521580 is a wasteful number, since it uses less digits than its factorization.

81802521580 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 314625105 (or 314625103 counting only the distinct ones).

The product of its (nonzero) digits is 51200, while the sum is 40.

The spelling of 81802521580 in words is "eighty-one billion, eight hundred two million, five hundred twenty-one thousand, five hundred eighty".