20556020 has 24 divisors (see below), whose sum is σ = 45045504. Its totient is φ = 7864736.

The previous prime is 20556017. The next prime is 20556023. The reversal of 20556020 is 2065502.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (20556017) and next prime (20556023).

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a junction number, because it is equal to n+sod(n) for n = 20555983 and 20556001.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20556023) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 21884 + ... + 22803.

It is an arithmetic number, because the mean of its divisors is an integer number (1876896).

Almost surely, 2^20556020 is an apocalyptic number.

20556020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20556020 is an abundant number, since it is smaller than the sum of its proper divisors (24489484).

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

20556020 is a wasteful number, since it uses less digits than its factorization.

20556020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 44719 (or 44717 counting only the distinct ones).

The product of its (nonzero) digits is 600, while the sum is 20.

The square root of 20556020 is about 4533.8747225745. The cubic root of 20556020 is about 273.9342552760.

The spelling of 20556020 in words is "twenty million, five hundred fifty-six thousand, twenty".