20609920 has 32 divisors (see below), whose sum is σ = 49272120. Its totient is φ = 8243712.

The previous prime is 20609917. The next prime is 20609929. The reversal of 20609920 is 2990602.

It is a tau number, because it is divible by the number of its divisors (32).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20609929) 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, 15462 + ... + 16741.

Almost surely, 2^20609920 is an apocalyptic number.

20609920 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20609920 is an abundant number, since it is smaller than the sum of its proper divisors (28662200).

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

20609920 is an equidigital number, since it uses as much as digits as its factorization.

20609920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32222 (or 32210 counting only the distinct ones).

The product of its (nonzero) digits is 1944, while the sum is 28.

The square root of 20609920 is about 4539.8149742032. The cubic root of 20609920 is about 274.1734742486.

The spelling of 20609920 in words is "twenty million, six hundred nine thousand, nine hundred twenty".