21161013664120 has 64 divisors (see below), whose sum is σ = 53148592506240. Its totient is φ = 7515962563200.

The previous prime is 21161013664099. The next prime is 21161013664139. The reversal of 21161013664120 is 2146631016112.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 559204486 + ... + 559242325.

It is an arithmetic number, because the mean of its divisors is an integer number (830446757910).

Almost surely, 2^{21161013664120} is an apocalyptic number.

21161013664120 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21161013664120 is an abundant number, since it is smaller than the sum of its proper divisors (31987578842120).

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

21161013664120 is a wasteful number, since it uses less digits than its factorization.

21161013664120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1118446876 (or 1118446872 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 34.

The spelling of 21161013664120 in words is "twenty-one trillion, one hundred sixty-one billion, thirteen million, six hundred sixty-four thousand, one hundred twenty".