25642491 has 32 divisors (see below), whose sum is σ = 40634880. Its totient is φ = 14079744.

The previous prime is 25642489. The next prime is 25642499. The reversal of 25642491 is 19424652.

It is not a de Polignac number, because 25642491 - 2¹ = 25642489 is a prime.

It is not an unprimeable number, because it can be changed into a prime (25642499) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 65725 + ... + 66113.

It is an arithmetic number, because the mean of its divisors is an integer number (1269840).

Almost surely, 2^25642491 is an apocalyptic number.

25642491 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

25642491 is a deficient number, since it is larger than the sum of its proper divisors (14992389).

25642491 is a wasteful number, since it uses less digits than its factorization.

25642491 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 515.

The product of its digits is 17280, while the sum is 33.

The square root of 25642491 is about 5063.8415259564. The cubic root of 25642491 is about 294.8854903648.

The spelling of 25642491 in words is "twenty-five million, six hundred forty-two thousand, four hundred ninety-one".