81002513000 has 32 divisors (see below), whose sum is σ = 189545882760. Its totient is φ = 32401004800.

The previous prime is 81002512967. The next prime is 81002513017. The reversal of 81002513000 is 31520018.

It can be written as a sum of positive squares in 4 ways, for example, as 16526130916 + 64476382084 = 128554^2 + 253922^2 .

It is a super-2 number, since 2×81002513000² (a number of 23 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 40500257 + ... + 40502256.

Almost surely, 2^81002513000 is an apocalyptic number.

It is an amenable number.

81002513000 is an abundant number, since it is smaller than the sum of its proper divisors (108543369760).

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

81002513000 is a wasteful number, since it uses less digits than its factorization.

81002513000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 81002534 (or 81002520 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 20.

The spelling of 81002513000 in words is "eighty-one billion, two million, five hundred thirteen thousand".