25661004506 has 4 divisors (see below), whose sum is σ = 38491506762. Its totient is φ = 12830502252.

The previous prime is 25661004503. The next prime is 25661004511. The reversal of 25661004506 is 60540016652.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 22472708281 + 3188296225 = 149909^2 + 56465^2 .

It is not an unprimeable number, because it can be changed into a prime (25661004503) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6415251125 + ... + 6415251128.

Almost surely, 2^25661004506 is an apocalyptic number.

25661004506 is a deficient number, since it is larger than the sum of its proper divisors (12830502256).

25661004506 is a wasteful number, since it uses less digits than its factorization.

25661004506 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12830502255.

The product of its (nonzero) digits is 43200, while the sum is 35.

The spelling of 25661004506 in words is "twenty-five billion, six hundred sixty-one million, four thousand, five hundred six".