21213554564612 has 24 divisors (see below), whose sum is σ = 37300575006240. Its totient is φ = 10556249880960.

The previous prime is 21213554564581. The next prime is 21213554564687. The reversal of 21213554564612 is 21646545531212.

It is a happy number.

It is a Smith number, since the sum of its digits (47) coincides with the sum of the digits of its prime factors.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 36864839 + ... + 37435857.

It is an arithmetic number, because the mean of its divisors is an integer number (1554190625260).

Almost surely, 2^{21213554564612} is an apocalyptic number.

It is an amenable number.

21213554564612 is a deficient number, since it is larger than the sum of its proper divisors (16087020441628).

21213554564612 is a wasteful number, since it uses less digits than its factorization.

21213554564612 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 615251 (or 615249 counting only the distinct ones).

The product of its digits is 1728000, while the sum is 47.

The spelling of 21213554564612 in words is "twenty-one trillion, two hundred thirteen billion, five hundred fifty-four million, five hundred sixty-four thousand, six hundred twelve".