25661403 has 6 divisors (see below), whose sum is σ = 37066484. Its totient is φ = 17107596.

The previous prime is 25661371. The next prime is 25661407. The reversal of 25661403 is 30416652.

25661403 is a `hidden beast` number, since 256 + 6 + 1 + 403 = 666.

It is not a de Polignac number, because 25661403 - 2⁵ = 25661371 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (25661407) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1425625 + ... + 1425642.

Almost surely, 2^25661403 is an apocalyptic number.

25661403 is a deficient number, since it is larger than the sum of its proper divisors (11405081).

25661403 is a wasteful number, since it uses less digits than its factorization.

25661403 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2851273 (or 2851270 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 27.

The square root of 25661403 is about 5065.7085387930. The cubic root of 25661403 is about 294.9579677738.

It can be divided in two parts, 2566 and 1403, that added together give a square (3969 = 63²).

The spelling of 25661403 in words is "twenty-five million, six hundred sixty-one thousand, four hundred three".