21661043604162 has 16 divisors (see below), whose sum is σ = 43322889953952. Its totient is φ = 7220214077120.

The previous prime is 21661043604149. The next prime is 21661043604181. The reversal of 21661043604162 is 26140634016612.

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, 33096663 + ... + 33744794.

It is an arithmetic number, because the mean of its divisors is an integer number (2707680622122).

Almost surely, 2^{21661043604162} is an apocalyptic number.

21661043604162 is an abundant number, since it is smaller than the sum of its proper divisors (21661846349790).

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

21661043604162 is a wasteful number, since it uses less digits than its factorization.

21661043604162 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 66895473.

The product of its (nonzero) digits is 248832, while the sum is 42.

The spelling of 21661043604162 in words is "twenty-one trillion, six hundred sixty-one billion, forty-three million, six hundred four thousand, one hundred sixty-two".