20520900 has 81 divisors (see below), whose sum is σ = 64750413. Its totient is φ = 5436000.

The previous prime is 20520889. The next prime is 20520901. The reversal of 20520900 is 902502.

The square root of 20520900 is 4530.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 7387524 + 13133376 = 2718^2 + 3624^2 .

It is a super-2 number, since 2×20520900² = 842214673620000, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is not an unprimeable number, because it can be changed into a prime (20520901) 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 26 ways as a sum of consecutive naturals, for example, 135825 + ... + 135975.

Almost surely, 2^20520900 is an apocalyptic number.

20520900 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

20520900 is the 4530-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20520900

20520900 is an abundant number, since it is smaller than the sum of its proper divisors (44229513).

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

20520900 is a wasteful number, since it uses less digits than its factorization.

20520900 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 322 (or 161 counting only the distinct ones).

The product of its (nonzero) digits is 180, while the sum is 18.

The cubic root of 20520900 is about 273.7781606109.

The spelling of 20520900 in words is "twenty million, five hundred twenty thousand, nine hundred".