25621668 has 18 divisors (see below), whose sum is σ = 64765974. Its totient is φ = 8540544.

The previous prime is 25621667. The next prime is 25621691. The reversal of 25621668 is 86612652.

25621668 is a `hidden beast` number, since 25 + 621 + 6 + 6 + 8 = 666.

It can be written as a sum of positive squares in only one way, i.e., 19027044 + 6594624 = 4362^2 + 2568^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is a super-2 number, since 2×25621668² = 1312939742204448, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36), and also a Moran number because the ratio is a prime number: 711713 = 25621668 / (2 + 5 + 6 + 2 + 1 + 6 + 6 + 8).

It is not an unprimeable number, because it can be changed into a prime (25621663) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 355821 + ... + 355892.

Almost surely, 2^25621668 is an apocalyptic number.

It is an amenable number.

25621668 is an abundant number, since it is smaller than the sum of its proper divisors (39144306).

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

25621668 is a wasteful number, since it uses less digits than its factorization.

25621668 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 711723 (or 711718 counting only the distinct ones).

The product of its digits is 34560, while the sum is 36.

The square root of 25621668 is about 5061.7850606283. The cubic root of 25621668 is about 294.8056481032.

The spelling of 25621668 in words is "twenty-five million, six hundred twenty-one thousand, six hundred sixty-eight".