20507720 has 32 divisors (see below), whose sum is σ = 48150720. Its totient is φ = 7846080.

The previous prime is 20507717. The next prime is 20507737. The reversal of 20507720 is 2770502.

It is a Harshad number since it is a multiple of its sum of digits (23).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10226 + ... + 12065.

It is an arithmetic number, because the mean of its divisors is an integer number (1504710).

Almost surely, 2^20507720 is an apocalyptic number.

20507720 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20507720 is an abundant number, since it is smaller than the sum of its proper divisors (27643000).

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

20507720 is a wasteful number, since it uses less digits than its factorization.

20507720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22325 (or 22321 counting only the distinct ones).

The product of its (nonzero) digits is 980, while the sum is 23.

The square root of 20507720 is about 4528.5450202024. The cubic root of 20507720 is about 273.7195347066.

The spelling of 20507720 in words is "twenty million, five hundred seven thousand, seven hundred twenty".