21621253326554 has 16 divisors (see below), whose sum is σ = 37125078660288. Its totient is φ = 9251233186272.

The previous prime is 21621253326523. The next prime is 21621253326571. The reversal of 21621253326554 is 45562335212612.

It is a super-2 number, since 2×21621253326554² (a number of 27 digits) contains 22 as substring.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21621253326499 and 21621253326508.

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, 1251511004 + ... + 1251528279.

It is an arithmetic number, because the mean of its divisors is an integer number (2320317416268).

Almost surely, 2^{21621253326554} is an apocalyptic number.

21621253326554 is a deficient number, since it is larger than the sum of its proper divisors (15503825333734).

21621253326554 is a wasteful number, since it uses less digits than its factorization.

21621253326554 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2503039909.

The product of its digits is 2592000, while the sum is 47.

The spelling of 21621253326554 in words is "twenty-one trillion, six hundred twenty-one billion, two hundred fifty-three million, three hundred twenty-six thousand, five hundred fifty-four".