25640545 has 16 divisors (see below), whose sum is σ = 35290368. Its totient is φ = 17519040.

The previous prime is 25640543. The next prime is 25640579. The reversal of 25640545 is 54504652.

It is not a de Polignac number, because 25640545 - 2¹ = 25640543 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (25640543) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9940 + ... + 12250.

It is an arithmetic number, because the mean of its divisors is an integer number (2205648).

Almost surely, 2^25640545 is an apocalyptic number.

It is an amenable number.

25640545 is a deficient number, since it is larger than the sum of its proper divisors (9649823).

25640545 is a wasteful number, since it uses less digits than its factorization.

25640545 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2640.

The product of its (nonzero) digits is 24000, while the sum is 31.

The square root of 25640545 is about 5063.6493756973. The cubic root of 25640545 is about 294.8780305892.

The spelling of 25640545 in words is "twenty-five million, six hundred forty thousand, five hundred forty-five".