25505664 has 64 divisors (see below), whose sum is σ = 68413440. Its totient is φ = 8418816.

The previous prime is 25505647. The next prime is 25505677. The reversal of 25505664 is 46650552.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (64).

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, 48507 + ... + 49029.

It is an arithmetic number, because the mean of its divisors is an integer number (1068960).

Almost surely, 2^25505664 is an apocalyptic number.

25505664 is a gapful number since it is divisible by the number (24) 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 25505664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34206720).

25505664 is an abundant number, since it is smaller than the sum of its proper divisors (42907776).

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

25505664 is a wasteful number, since it uses less digits than its factorization.

25505664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 667 (or 655 counting only the distinct ones).

The product of its (nonzero) digits is 36000, while the sum is 33.

The square root of 25505664 is about 5050.3132576109. The cubic root of 25505664 is about 294.3600568052.

The spelling of 25505664 in words is "twenty-five million, five hundred five thousand, six hundred sixty-four".