21090762331025 has 12 divisors (see below), whose sum is σ = 26153131365900. Its totient is φ = 16872231751680.

The previous prime is 21090762330973. The next prime is 21090762331027. The reversal of 21090762331025 is 52013326709012.

It is a Cunningham number, because it is equal to 4592468²+1.

It can be written as a sum of positive squares in 6 ways, for example, as 1653518235664 + 19437244095361 = 1285892^2 + 4408769^2 .

It is not a de Polignac number, because 21090762331025 - 2²⁶ = 21090695222161 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21090762331027) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 8312240 + ... + 10548689.

It is an arithmetic number, because the mean of its divisors is an integer number (2179427613825).

Almost surely, 2^{21090762331025} is an apocalyptic number.

21090762331025 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21090762331025 is a deficient number, since it is larger than the sum of its proper divisors (5062369034875).

21090762331025 is a wasteful number, since it uses less digits than its factorization.

21090762331025 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18905668 (or 18905663 counting only the distinct ones).

The product of its (nonzero) digits is 136080, while the sum is 41.

The spelling of 21090762331025 in words is "twenty-one trillion, ninety billion, seven hundred sixty-two million, three hundred thirty-one thousand, twenty-five".