81263496972 has 48 divisors (see below), whose sum is σ = 216717412352. Its totient is φ = 23216561280.

The previous prime is 81263496971. The next prime is 81263496989. The reversal of 81263496972 is 27969436218.

It is not an unprimeable number, because it can be changed into a prime (81263496971) 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, 1835448 + ... + 1879200.

Almost surely, 2^81263496972 is an apocalyptic number.

It is an amenable number.

81263496972 is an abundant number, since it is smaller than the sum of its proper divisors (135453915380).

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

81263496972 is a wasteful number, since it uses less digits than its factorization.

81263496972 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 65878 (or 65876 counting only the distinct ones).

The product of its digits is 7838208, while the sum is 57.

The spelling of 81263496972 in words is "eighty-one billion, two hundred sixty-three million, four hundred ninety-six thousand, nine hundred seventy-two".