81217856002 has 16 divisors (see below), whose sum is σ = 124126256160. Its totient is φ = 39847154688.

The previous prime is 81217855991. The next prime is 81217856021. The reversal of 81217856002 is 20065871218.

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, 1144752 + ... + 1213627.

It is an arithmetic number, because the mean of its divisors is an integer number (7757891010).

Almost surely, 2^81217856002 is an apocalyptic number.

81217856002 is a deficient number, since it is larger than the sum of its proper divisors (42908400158).

81217856002 is a wasteful number, since it uses less digits than its factorization.

81217856002 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2358705.

The product of its (nonzero) digits is 53760, while the sum is 40.

The spelling of 81217856002 in words is "eighty-one billion, two hundred seventeen million, eight hundred fifty-six thousand, two".