16639988 has 6 divisors (see below), whose sum is σ = 29119986. Its totient is φ = 8319992.

The previous prime is 16639969. The next prime is 16639993. The reversal of 16639988 is 88993661.

It can be written as a sum of positive squares in only one way, i.e., 12687844 + 3952144 = 3562^2 + 1988^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2079995 + ... + 2080002.

It is an arithmetic number, because the mean of its divisors is an integer number (4853331).

Almost surely, 2^16639988 is an apocalyptic number.

It is an amenable number.

16639988 is a deficient number, since it is larger than the sum of its proper divisors (12479998).

16639988 is a wasteful number, since it uses less digits than its factorization.

16639988 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4160001 (or 4159999 counting only the distinct ones).

The product of its digits is 559872, while the sum is 50.

The square root of 16639988 is about 4079.2141400029. The cubic root of 16639988 is about 255.3001105841.

The spelling of 16639988 in words is "sixteen million, six hundred thirty-nine thousand, nine hundred eighty-eight".