21660535562444 has 12 divisors (see below), whose sum is σ = 40135698248184. Its totient is φ = 10193193205824.

The previous prime is 21660535562399. The next prime is 21660535562467. The reversal of 21660535562444 is 44426553506612.

It is a super-2 number, since 2×21660535562444² (a number of 27 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 159268643774 + ... + 159268643909.

It is an arithmetic number, because the mean of its divisors is an integer number (3344641520682).

Almost surely, 2^{21660535562444} is an apocalyptic number.

It is an amenable number.

21660535562444 is a deficient number, since it is larger than the sum of its proper divisors (18475162685740).

21660535562444 is a wasteful number, since it uses less digits than its factorization.

21660535562444 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 318537287704 (or 318537287702 counting only the distinct ones).

The product of its (nonzero) digits is 20736000, while the sum is 53.

The spelling of 21660535562444 in words is "twenty-one trillion, six hundred sixty billion, five hundred thirty-five million, five hundred sixty-two thousand, four hundred forty-four".