6635021990 has 16 divisors (see below), whose sum is σ = 11961340848. Its totient is φ = 2649941856.

The previous prime is 6635021989. The next prime is 6635022011. The reversal of 6635021990 is 991205366.

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, 501512 + ... + 514571.

It is an arithmetic number, because the mean of its divisors is an integer number (747583803).

Almost surely, 2^6635021990 is an apocalyptic number.

6635021990 is a deficient number, since it is larger than the sum of its proper divisors (5326318858).

6635021990 is a wasteful number, since it uses less digits than its factorization.

6635021990 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1016743.

The product of its (nonzero) digits is 87480, while the sum is 41.

The square root of 6635021990 is about 81455.6443102625. The cubic root of 6635021990 is about 1879.0894555116.

The spelling of 6635021990 in words is "six billion, six hundred thirty-five million, twenty-one thousand, nine hundred ninety".