6635389605625 has 405 divisors, whose sum is σ = 10582400189361. Its totient is φ = 4154451840000.

The previous prime is 6635389605619. The next prime is 6635389605731. The reversal of 6635389605625 is 5265069835366.

It is a happy number.

The square root of 6635389605625 is 2575925.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 22 ways, for example, as 6626778508009 + 8611097616 = 2574253^2 + 92796^2 .

It is not a de Polignac number, because 6635389605625 - 2¹⁹ = 6635389081337 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 404 ways as a sum of consecutive naturals, for example, 228806538111 + ... + 228806538139.

Almost surely, 2^{6635389605625} is an apocalyptic number.

6635389605625 is the 2575925-th square number.

6635389605625 is the 1287963-rd centered octagonal number.

It is an amenable number.

6635389605625 is a deficient number, since it is larger than the sum of its proper divisors (3947010583736).

6635389605625 is a wasteful number, since it uses less digits than its factorization.

6635389605625 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 172 (or 81 counting only the distinct ones).

The product of its (nonzero) digits is 209952000, while the sum is 64.

Multiplying 6635389605625 by its sum of digits (64), we get a square (424664934760000 = 20607400²).

The spelling of 6635389605625 in words is "six trillion, six hundred thirty-five billion, three hundred eighty-nine million, six hundred five thousand, six hundred twenty-five".