25321612321 has 2 divisors, whose sum is σ = 25321612322. Its totient is φ = 25321612320.

The previous prime is 25321612297. The next prime is 25321612357. The reversal of 25321612321 is 12321612352.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13558040721 + 11763571600 = 116439^2 + 108460^2 .

It is a cyclic number.

It is not a de Polignac number, because 25321612321 - 2⁵ = 25321612289 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 25321612321.

It is not a weakly prime, because it can be changed into another prime (25321613321) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12660806160 + 12660806161.

It is an arithmetic number, because the mean of its divisors is an integer number (12660806161).

Almost surely, 2^25321612321 is an apocalyptic number.

It is an amenable number.

25321612321 is a deficient number, since it is larger than the sum of its proper divisors (1).

25321612321 is an equidigital number, since it uses as much as digits as its factorization.

25321612321 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4320, while the sum is 28.

The spelling of 25321612321 in words is "twenty-five billion, three hundred twenty-one million, six hundred twelve thousand, three hundred twenty-one".