16989990 has 64 divisors (see below), whose sum is σ = 44029440. Its totient is φ = 4181760.

The previous prime is 16989967. The next prime is 16989991. The reversal of 16989990 is 9998961.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16989991) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 23007 + ... + 23733.

It is an arithmetic number, because the mean of its divisors is an integer number (687960).

Almost surely, 2^16989990 is an apocalyptic number.

16989990 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 16989990, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22014720).

16989990 is an abundant number, since it is smaller than the sum of its proper divisors (27039450).

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

16989990 is a wasteful number, since it uses less digits than its factorization.

16989990 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 797.

The product of its (nonzero) digits is 314928, while the sum is 51.

The square root of 16989990 is about 4121.8915560699. The cubic root of 16989990 is about 257.0776814537.

The spelling of 16989990 in words is "sixteen million, nine hundred eighty-nine thousand, nine hundred ninety".