20739990 has 16 divisors (see below), whose sum is σ = 49776048. Its totient is φ = 5530656.

The previous prime is 20739947. The next prime is 20740003. The reversal of 20739990 is 9993702.

It is a Curzon number.

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, 345637 + ... + 345696.

It is an arithmetic number, because the mean of its divisors is an integer number (3111003).

Almost surely, 2^20739990 is an apocalyptic number.

20739990 is an abundant number, since it is smaller than the sum of its proper divisors (29036058).

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

20739990 is a wasteful number, since it uses less digits than its factorization.

20739990 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 691343.

The product of its (nonzero) digits is 30618, while the sum is 39.

The square root of 20739990 is about 4554.1179167870. The cubic root of 20739990 is about 274.7490382626.

The spelling of 20739990 in words is "twenty million, seven hundred thirty-nine thousand, nine hundred ninety".