20655520 has 24 divisors (see below), whose sum is σ = 48799044. Its totient is φ = 8262144.

The previous prime is 20655473. The next prime is 20655529. The reversal of 20655520 is 2555602.

It can be written as a sum of positive squares in 2 ways, for example, as 20034576 + 620944 = 4476^2 + 788^2 .

It is not an unprimeable number, because it can be changed into a prime (20655529) 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, 64389 + ... + 64708.

Almost surely, 2^20655520 is an apocalyptic number.

20655520 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20655520 is an abundant number, since it is smaller than the sum of its proper divisors (28143524).

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

20655520 is a wasteful number, since it uses less digits than its factorization.

20655520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 129112 (or 129104 counting only the distinct ones).

The product of its (nonzero) digits is 3000, while the sum is 25.

The square root of 20655520 is about 4544.8344304276. The cubic root of 20655520 is about 274.3755306884.

The spelling of 20655520 in words is "twenty million, six hundred fifty-five thousand, five hundred twenty".