25529640 has 64 divisors (see below), whose sum is σ = 77587200. Its totient is φ = 6719232.

The previous prime is 25529639. The next prime is 25529641. The reversal of 25529640 is 4692552.

It is an interprime number because it is at equal distance from previous prime (25529639) and next prime (25529641).

It is not an unprimeable number, because it can be changed into a prime (25529641) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8134 + ... + 10826.

It is an arithmetic number, because the mean of its divisors is an integer number (1212300).

Almost surely, 2^25529640 is an apocalyptic number.

25529640 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 25529640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38793600).

25529640 is an abundant number, since it is smaller than the sum of its proper divisors (52057560).

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

25529640 is a wasteful number, since it uses less digits than its factorization.

25529640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2786 (or 2782 counting only the distinct ones).

The product of its (nonzero) digits is 21600, while the sum is 33.

The square root of 25529640 is about 5052.6864141761. The cubic root of 25529640 is about 294.4522633368.

The spelling of 25529640 in words is "twenty-five million, five hundred twenty-nine thousand, six hundred forty".