21623125305551 has 32 divisors (see below), whose sum is σ = 27314671641600. Its totient is φ = 16627702809600.

The previous prime is 21623125305539. The next prime is 21623125305559. The reversal of 21623125305551 is 15550352132612.

It is a cyclic number.

It is not a de Polignac number, because 21623125305551 - 2³⁸ = 21348247398607 is a prime.

It is a super-2 number, since 2×21623125305551² (a number of 27 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21623125305499 and 21623125305508.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21623125305559) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1540955 + ... + 6754316.

It is an arithmetic number, because the mean of its divisors is an integer number (853583488800).

Almost surely, 2^{21623125305551} is an apocalyptic number.

21623125305551 is a deficient number, since it is larger than the sum of its proper divisors (5691546336049).

21623125305551 is a wasteful number, since it uses less digits than its factorization.

21623125305551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8295735.

The product of its (nonzero) digits is 270000, while the sum is 41.

The spelling of 21623125305551 in words is "twenty-one trillion, six hundred twenty-three billion, one hundred twenty-five million, three hundred five thousand, five hundred fifty-one".