21133621156554 has 32 divisors (see below), whose sum is σ = 47306402605440. Its totient is φ = 6993120380256.

The previous prime is 21133621156519. The next prime is 21133621156573. The reversal of 21133621156554 is 45565112633112.

It is a happy number.

21133621156554 is a `hidden beast` number, since 2 + 1 + 1 + 3 + 3 + 621 + 15 + 6 + 5 + 5 + 4 = 666.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1428326014 + ... + 1428340809.

It is an arithmetic number, because the mean of its divisors is an integer number (1478325081420).

Almost surely, 2^{21133621156554} is an apocalyptic number.

21133621156554 is an abundant number, since it is smaller than the sum of its proper divisors (26172781448886).

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

21133621156554 is a wasteful number, since it uses less digits than its factorization.

21133621156554 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2856666971 (or 2856666965 counting only the distinct ones).

The product of its digits is 648000, while the sum is 45.

Adding to 21133621156554 its reverse (45565112633112), we get a palindrome (66698733789666).

The spelling of 21133621156554 in words is "twenty-one trillion, one hundred thirty-three billion, six hundred twenty-one million, one hundred fifty-six thousand, five hundred fifty-four".