21161014556004 has 288 divisors, whose sum is σ = 57732515672832. Its totient is φ = 6772481280000.

The previous prime is 21161014555981. The next prime is 21161014556021. The reversal of 21161014556004 is 40065541016112.

21161014556004 is a `hidden beast` number, since 2 + 1 + 1 + 6 + 1 + 0 + 1 + 45 + 5 + 600 + 4 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 21161014556004.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 672167944 + ... + 672199424.

It is an arithmetic number, because the mean of its divisors is an integer number (200460123864).

Almost surely, 2^{21161014556004} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21161014556004, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28866257836416).

21161014556004 is an abundant number, since it is smaller than the sum of its proper divisors (36571501116828).

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

21161014556004 is a wasteful number, since it uses less digits than its factorization.

21161014556004 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31809 (or 31795 counting only the distinct ones).

The product of its (nonzero) digits is 28800, while the sum is 36.

The spelling of 21161014556004 in words is "twenty-one trillion, one hundred sixty-one billion, fourteen million, five hundred fifty-six thousand, four".