6638401625 has 16 divisors (see below), whose sum is σ = 8287868160. Its totient is φ = 5308706800.

The previous prime is 6638401613. The next prime is 6638401661. The reversal of 6638401625 is 5261048366.

It is not a de Polignac number, because 6638401625 - 2¹⁴ = 6638385241 is a prime.

It is a super-2 number, since 2×6638401625² = 88136752269605281250, which contains 22 as substring.

It is a Curzon number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 381362 + ... + 398388.

It is an arithmetic number, because the mean of its divisors is an integer number (517991760).

Almost surely, 2^6638401625 is an apocalyptic number.

It is an amenable number.

6638401625 is a deficient number, since it is larger than the sum of its proper divisors (1649466535).

6638401625 is a wasteful number, since it uses less digits than its factorization.

6638401625 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20161 (or 20151 counting only the distinct ones).

The product of its (nonzero) digits is 207360, while the sum is 41.

The square root of 6638401625 is about 81476.3869167012. The cubic root of 6638401625 is about 1879.4084475986.

The spelling of 6638401625 in words is "six billion, six hundred thirty-eight million, four hundred one thousand, six hundred twenty-five".