20404520 has 32 divisors (see below), whose sum is σ = 46093320. Its totient is φ = 8129280.

The previous prime is 20404493. The next prime is 20404547. The reversal of 20404520 is 2540402.

It is an interprime number because it is at equal distance from previous prime (20404493) and next prime (20404547).

It can be written as a sum of positive squares in 4 ways, for example, as 14577124 + 5827396 = 3818^2 + 2414^2 .

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, 10850 + ... + 12590.

Almost surely, 2^20404520 is an apocalyptic number.

20404520 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20404520 is an abundant number, since it is smaller than the sum of its proper divisors (25688800).

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

20404520 is a wasteful number, since it uses less digits than its factorization.

20404520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2045 (or 2041 counting only the distinct ones).

The product of its (nonzero) digits is 320, while the sum is 17.

The square root of 20404520 is about 4517.1362609512. The cubic root of 20404520 is about 273.2596205485.

Adding to 20404520 its reverse (2540402), we get a palindrome (22944922).

The spelling of 20404520 in words is "twenty million, four hundred four thousand, five hundred twenty".