25036665621 has 16 divisors (see below), whose sum is σ = 37305188928. Its totient is φ = 14803644800.

The previous prime is 25036665607. The next prime is 25036665649. The reversal of 25036665621 is 12656663052.

It is a cyclic number.

It is not a de Polignac number, because 25036665621 - 2¹¹ = 25036663573 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25036665691) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9250926 + ... + 9253631.

It is an arithmetic number, because the mean of its divisors is an integer number (2331574308).

Almost surely, 2^25036665621 is an apocalyptic number.

It is an amenable number.

25036665621 is a deficient number, since it is larger than the sum of its proper divisors (12268523307).

25036665621 is a wasteful number, since it uses less digits than its factorization.

25036665621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18504612.

The product of its (nonzero) digits is 388800, while the sum is 42.

The spelling of 25036665621 in words is "twenty-five billion, thirty-six million, six hundred sixty-five thousand, six hundred twenty-one".