21621271305425 has 12 divisors (see below), whose sum is σ = 29247683366256. Its totient is φ = 15724560949200.

The previous prime is 21621271305391. The next prime is 21621271305451. The reversal of 21621271305425 is 52450317212612.

It is not a de Polignac number, because 21621271305425 - 2²⁰ = 21621270256849 is a prime.

It is a Duffinian number.

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 11 ways as a sum of consecutive naturals, for example, 39311402099 + ... + 39311402648.

It is an arithmetic number, because the mean of its divisors is an integer number (2437306947188).

Almost surely, 2^{21621271305425} is an apocalyptic number.

21621271305425 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21621271305425 is a deficient number, since it is larger than the sum of its proper divisors (7626412060831).

21621271305425 is a wasteful number, since it uses less digits than its factorization.

21621271305425 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 78622804768 (or 78622804763 counting only the distinct ones).

The product of its (nonzero) digits is 201600, while the sum is 41.

The spelling of 21621271305425 in words is "twenty-one trillion, six hundred twenty-one billion, two hundred seventy-one million, three hundred five thousand, four hundred twenty-five".