19980990 has 24 divisors (see below), whose sum is σ = 51950808. Its totient is φ = 5328240.

The previous prime is 19980973. The next prime is 19981007. The reversal of 19980990 is 9908991.

It is an interprime number because it is at equal distance from previous prime (19980973) and next prime (19981007).

It is a super-2 number, since 2×19980990² = 798479922760200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 110916 + ... + 111095.

It is an arithmetic number, because the mean of its divisors is an integer number (2164617).

Almost surely, 2^19980990 is an apocalyptic number.

19980990 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

19980990 is an abundant number, since it is smaller than the sum of its proper divisors (31969818).

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

19980990 is a wasteful number, since it uses less digits than its factorization.

19980990 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 222024 (or 222021 counting only the distinct ones).

The product of its (nonzero) digits is 52488, while the sum is 45.

The square root of 19980990 is about 4470.0100671028. The cubic root of 19980990 is about 271.3557325987.

The spelling of 19980990 in words is "nineteen million, nine hundred eighty thousand, nine hundred ninety".