25293403521 has 45 divisors (see below), whose sum is σ = 38818075219. Its totient is φ = 16412824800.

The previous prime is 25293403493. The next prime is 25293403523. The reversal of 25293403521 is 12530439252.

The square root of 25293403521 is 159039.

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

25293403521 is a `hidden beast` number, since 2 + 5 + 2 + 93 + 40 + 3 + 521 = 666.

It can be written as a sum of positive squares in only one way, i.e., 1218777921 + 24074625600 = 34911^2 + 155160^2 .

It is not a de Polignac number, because 25293403521 - 2¹⁹ = 25292879233 is a prime.

It is a super-2 number, since 2×25293403521² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (25293403523) by changing a digit.

It is a polite number, since it can be written in 44 ways as a sum of consecutive naturals, for example, 58685176 + ... + 58685606.

Almost surely, 2^25293403521 is an apocalyptic number.

25293403521 is the 159039-th square number.

25293403521 is the 79520-th centered octagonal number.

It is an amenable number.

25293403521 is a deficient number, since it is larger than the sum of its proper divisors (13524671698).

25293403521 is an frugal number, since it uses more digits than its factorization.

25293403521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 956 (or 475 counting only the distinct ones).

The product of its (nonzero) digits is 64800, while the sum is 36.

Multiplying 25293403521 by its sum of digits (36), we get a square (910562526756 = 954234²).

The spelling of 25293403521 in words is "twenty-five billion, two hundred ninety-three million, four hundred three thousand, five hundred twenty-one".