25601236421 has 2 divisors, whose sum is σ = 25601236422. Its totient is φ = 25601236420.

The previous prime is 25601236387. The next prime is 25601236459. The reversal of 25601236421 is 12463210652.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 24595648900 + 1005587521 = 156830^2 + 31711^2 .

It is a cyclic number.

It is not a de Polignac number, because 25601236421 - 2³⁰ = 24527494597 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (25601236021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12800618210 + 12800618211.

It is an arithmetic number, because the mean of its divisors is an integer number (12800618211).

Almost surely, 2^25601236421 is an apocalyptic number.

It is an amenable number.

25601236421 is a deficient number, since it is larger than the sum of its proper divisors (1).

25601236421 is an equidigital number, since it uses as much as digits as its factorization.

25601236421 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 17280, while the sum is 32.

The spelling of 25601236421 in words is "twenty-five billion, six hundred one million, two hundred thirty-six thousand, four hundred twenty-one".