20319990 has 16 divisors (see below), whose sum is σ = 48768048. Its totient is φ = 5418656.

The previous prime is 20319989. The next prime is 20320007. The reversal of 20319990 is 9991302.

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, 338637 + ... + 338696.

It is an arithmetic number, because the mean of its divisors is an integer number (3048003).

Almost surely, 2^20319990 is an apocalyptic number.

20319990 is an abundant number, since it is smaller than the sum of its proper divisors (28448058).

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

20319990 is a wasteful number, since it uses less digits than its factorization.

20319990 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 677343.

The product of its (nonzero) digits is 4374, while the sum is 33.

The square root of 20319990 is about 4507.7699586381. The cubic root of 20319990 is about 272.8817531884.

It can be divided in two parts, 2031 and 9990, that added together give a palindrome (12021).

The spelling of 20319990 in words is "twenty million, three hundred nineteen thousand, nine hundred ninety".