21655212164446 has 16 divisors (see below), whose sum is σ = 37123610166144. Its totient is φ = 9280707885144.

The previous prime is 21655212164393. The next prime is 21655212164449. The reversal of 21655212164446 is 64446121255612.

It is a self number, because there is not a number n which added to its sum of digits gives 21655212164446.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21655212164449) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6719800 + ... + 9405643.

It is an arithmetic number, because the mean of its divisors is an integer number (2320225635384).

Almost surely, 2^{21655212164446} is an apocalyptic number.

21655212164446 is a deficient number, since it is larger than the sum of its proper divisors (15468398001698).

21655212164446 is a wasteful number, since it uses less digits than its factorization.

21655212164446 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16221375.

The product of its digits is 2764800, while the sum is 49.

The spelling of 21655212164446 in words is "twenty-one trillion, six hundred fifty-five billion, two hundred twelve million, one hundred sixty-four thousand, four hundred forty-six".