6638946138 has 56 divisors (see below), whose sum is σ = 16288183296. Its totient is φ = 2011797000.

The previous prime is 6638946089. The next prime is 6638946151. The reversal of 6638946138 is 8316498366.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

It is a polite number, since it can be written in 27 ways as a sum of consecutive naturals, for example, 190938 + ... + 223013.

It is an arithmetic number, because the mean of its divisors is an integer number (290860416).

Almost surely, 2^6638946138 is an apocalyptic number.

6638946138 is an abundant number, since it is smaller than the sum of its proper divisors (9649237158).

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

6638946138 is a wasteful number, since it uses less digits than its factorization.

6638946138 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 413982 (or 413967 counting only the distinct ones).

The product of its digits is 4478976, while the sum is 54.

The square root of 6638946138 is about 81479.7283868816. The cubic root of 6638946138 is about 1879.4598321744.

The spelling of 6638946138 in words is "six billion, six hundred thirty-eight million, nine hundred forty-six thousand, one hundred thirty-eight".