21064625425 has 12 divisors (see below), whose sum is σ = 26295443100. Its totient is φ = 16738598720.

The previous prime is 21064625423. The next prime is 21064625431. The reversal of 21064625425 is 52452646012.

It is a happy number.

It can be written as a sum of positive squares in 6 ways, for example, as 18740241 + 21045885184 = 4329^2 + 145072^2 .

It is not a de Polignac number, because 21064625425 - 2¹ = 21064625423 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21064625423) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2823742 + ... + 2831191.

It is an arithmetic number, because the mean of its divisors is an integer number (2191286925).

Almost surely, 2^21064625425 is an apocalyptic number.

21064625425 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21064625425 is a deficient number, since it is larger than the sum of its proper divisors (5230817675).

21064625425 is a wasteful number, since it uses less digits than its factorization.

21064625425 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5655092 (or 5655087 counting only the distinct ones).

The product of its (nonzero) digits is 115200, while the sum is 37.

The spelling of 21064625425 in words is "twenty-one billion, sixty-four million, six hundred twenty-five thousand, four hundred twenty-five".