25543640 has 32 divisors (see below), whose sum is σ = 57780000. Its totient is φ = 10162944.

The previous prime is 25543631. The next prime is 25543663. The reversal of 25543640 is 4634552.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6356 + ... + 9564.

It is an arithmetic number, because the mean of its divisors is an integer number (1805625).

Almost surely, 2^25543640 is an apocalyptic number.

25543640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

25543640 is an abundant number, since it is smaller than the sum of its proper divisors (32236360).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

25543640 is a wasteful number, since it uses less digits than its factorization.

25543640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3419 (or 3415 counting only the distinct ones).

The product of its (nonzero) digits is 14400, while the sum is 29.

The square root of 25543640 is about 5054.0716259270. The cubic root of 25543640 is about 294.5060776271.

The spelling of 25543640 in words is "twenty-five million, five hundred forty-three thousand, six hundred forty".