25451640 has 144 divisors (see below), whose sum is σ = 88522200. Its totient is φ = 6324480.

The previous prime is 25451633. The next prime is 25451641. The reversal of 25451640 is 4615452.

It is a hoax number, since the sum of its digits (27) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25451641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 417210 + ... + 417270.

Almost surely, 2^25451640 is an apocalyptic number.

25451640 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 25451640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (44261100).

25451640 is an abundant number, since it is smaller than the sum of its proper divisors (63070560).

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

25451640 is a wasteful number, since it uses less digits than its factorization.

25451640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 158 (or 90 counting only the distinct ones).

The product of its (nonzero) digits is 4800, while the sum is 27.

The square root of 25451640 is about 5044.9618432650. The cubic root of 25451640 is about 294.1520801412.

The spelling of 25451640 in words is "twenty-five million, four hundred fifty-one thousand, six hundred forty".