20439040 has 56 divisors (see below), whose sum is σ = 49149000. Its totient is φ = 8159232.

The previous prime is 20439017. The next prime is 20439043. The reversal of 20439040 is 4093402.

It is a super-2 number, since 2×20439040² = 835508712243200, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20439043) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 40711 + ... + 41209.

Almost surely, 2^20439040 is an apocalyptic number.

20439040 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20439040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24574500).

20439040 is an abundant number, since it is smaller than the sum of its proper divisors (28709960).

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

20439040 is an frugal number, since it uses more digits than its factorization.

20439040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 530 (or 506 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 22.

The square root of 20439040 is about 4520.9556511870. The cubic root of 20439040 is about 273.4136323004.

The spelling of 20439040 in words is "twenty million, four hundred thirty-nine thousand, forty".