25404561 has 24 divisors (see below), whose sum is σ = 45165120. Its totient is φ = 13399776.

The previous prime is 25404527. The next prime is 25404563. The reversal of 25404561 is 16540452.

It is not a de Polignac number, because 25404561 - 2⁶ = 25404497 is a prime.

It is not an unprimeable number, because it can be changed into a prime (25404563) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 14691 + ... + 16328.

It is an arithmetic number, because the mean of its divisors is an integer number (1881880).

Almost surely, 2^25404561 is an apocalyptic number.

25404561 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

25404561 is a deficient number, since it is larger than the sum of its proper divisors (19760559).

25404561 is a wasteful number, since it uses less digits than its factorization.

25404561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31045 (or 31042 counting only the distinct ones).

The product of its (nonzero) digits is 4800, while the sum is 27.

The square root of 25404561 is about 5040.2937414401. The cubic root of 25404561 is about 293.9705995867.

The spelling of 25404561 in words is "twenty-five million, four hundred four thousand, five hundred sixty-one".