25456521601 has 27 divisors (see below), whose sum is σ = 30987444033. Its totient is φ = 20850124680.

The previous prime is 25456521533. The next prime is 25456521617. The reversal of 25456521601 is 10612565452.

The square root of 25456521601 is 159551.

It is a perfect power (a square), and thus also a powerful number.

It is not a de Polignac number, because 25456521601 - 2¹¹ = 25456519553 is a prime.

It is not an unprimeable number, because it can be changed into a prime (25456521401) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 25687216 + ... + 25688206.

Almost surely, 2^25456521601 is an apocalyptic number.

25456521601 is the 159551-st square number.

25456521601 is the 79776-th centered octagonal number.

It is an amenable number.

25456521601 is a deficient number, since it is larger than the sum of its proper divisors (5530922432).

25456521601 is an frugal number, since it uses more digits than its factorization.

25456521601 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2042 (or 1021 counting only the distinct ones).

The product of its (nonzero) digits is 72000, while the sum is 37.

The spelling of 25456521601 in words is "twenty-five billion, four hundred fifty-six million, five hundred twenty-one thousand, six hundred one".