25520653637 has 2 divisors, whose sum is σ = 25520653638. Its totient is φ = 25520653636.

The previous prime is 25520653619. The next prime is 25520653663. The reversal of 25520653637 is 73635602552.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21630761476 + 3889892161 = 147074^2 + 62369^2 .

It is a cyclic number.

It is not a de Polignac number, because 25520653637 - 2³⁰ = 24446911813 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (25520653607) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12760326818 + 12760326819.

It is an arithmetic number, because the mean of its divisors is an integer number (12760326819).

Almost surely, 2^25520653637 is an apocalyptic number.

It is an amenable number.

25520653637 is a deficient number, since it is larger than the sum of its proper divisors (1).

25520653637 is an equidigital number, since it uses as much as digits as its factorization.

25520653637 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1134000, while the sum is 44.

The spelling of 25520653637 in words is "twenty-five billion, five hundred twenty million, six hundred fifty-three thousand, six hundred thirty-seven".