25662631609 has 2 divisors, whose sum is σ = 25662631610. Its totient is φ = 25662631608.

The previous prime is 25662631597. The next prime is 25662631691. The reversal of 25662631609 is 90613626652.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 23676592384 + 1986039225 = 153872^2 + 44565^2 .

It is a cyclic number.

It is not a de Polignac number, because 25662631609 - 2¹¹ = 25662629561 is a prime.

It is a super-2 number, since 2×25662631609² (a number of 22 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (25662631109) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12831315804 + 12831315805.

It is an arithmetic number, because the mean of its divisors is an integer number (12831315805).

Almost surely, 2^25662631609 is an apocalyptic number.

It is an amenable number.

25662631609 is a deficient number, since it is larger than the sum of its proper divisors (1).

25662631609 is an equidigital number, since it uses as much as digits as its factorization.

25662631609 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 699840, while the sum is 46.

The spelling of 25662631609 in words is "twenty-five billion, six hundred sixty-two million, six hundred thirty-one thousand, six hundred nine".