25643680 has 48 divisors (see below), whose sum is σ = 61344864. Its totient is φ = 10128640.

The previous prime is 25643677. The next prime is 25643699. The reversal of 25643680 is 8634652.

It is a happy 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, 12315 + ... + 14245.

It is an arithmetic number, because the mean of its divisors is an integer number (1278018).

Almost surely, 2^25643680 is an apocalyptic number.

25643680 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 25643680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30672432).

25643680 is an abundant number, since it is smaller than the sum of its proper divisors (35701184).

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

25643680 is a wasteful number, since it uses less digits than its factorization.

25643680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2029 (or 2021 counting only the distinct ones).

The product of its (nonzero) digits is 34560, while the sum is 34.

The square root of 25643680 is about 5063.9589255838. The cubic root of 25643680 is about 294.8900480789.

Subtracting from 25643680 its reverse (8634652), we obtain a triangular number (17009028 = T₅₈₃₂).

The spelling of 25643680 in words is "twenty-five million, six hundred forty-three thousand, six hundred eighty".