21661519922106 has 16 divisors (see below), whose sum is σ = 44244806649984. Its totient is φ = 7066878839744.

The previous prime is 21661519922057. The next prime is 21661519922143. The reversal of 21661519922106 is 60122991516612.

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, 38406949935 + ... + 38406950498.

It is an arithmetic number, because the mean of its divisors is an integer number (2765300415624).

Almost surely, 2^{21661519922106} is an apocalyptic number.

21661519922106 is an abundant number, since it is smaller than the sum of its proper divisors (22583286727878).

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

21661519922106 is a wasteful number, since it uses less digits than its factorization.

21661519922106 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 76813900485.

The product of its (nonzero) digits is 699840, while the sum is 51.

The spelling of 21661519922106 in words is "twenty-one trillion, six hundred sixty-one billion, five hundred nineteen million, nine hundred twenty-two thousand, one hundred six".