16990638 has 16 divisors (see below), whose sum is σ = 38835840. Its totient is φ = 4854456.

The previous prime is 16990613. The next prime is 16990639. The reversal of 16990638 is 83609961.

It is a Harshad number since it is a multiple of its sum of digits (42), and also a Moran number because the ratio is a prime number: 404539 = 16990638 / (1 + 6 + 9 + 9 + 0 + 6 + 3 + 8).

It is a self number, because there is not a number n which added to its sum of digits gives 16990638.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16990639) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 202228 + ... + 202311.

It is an arithmetic number, because the mean of its divisors is an integer number (2427240).

Almost surely, 2^16990638 is an apocalyptic number.

16990638 is an abundant number, since it is smaller than the sum of its proper divisors (21845202).

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

16990638 is a wasteful number, since it uses less digits than its factorization.

16990638 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 404551.

The product of its (nonzero) digits is 69984, while the sum is 42.

The square root of 16990638 is about 4121.9701600084. The cubic root of 16990638 is about 257.0809497354.

The spelling of 16990638 in words is "sixteen million, nine hundred ninety thousand, six hundred thirty-eight".