20256580 has 12 divisors (see below), whose sum is σ = 42538860. Its totient is φ = 8102624.

The previous prime is 20256559. The next prime is 20256581. The reversal of 20256580 is 8565202.

It can be written as a sum of positive squares in 2 ways, for example, as 2262016 + 17994564 = 1504^2 + 4242^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20256581) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 506395 + ... + 506434.

It is an arithmetic number, because the mean of its divisors is an integer number (3544905).

Almost surely, 2^20256580 is an apocalyptic number.

20256580 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20256580 is an abundant number, since it is smaller than the sum of its proper divisors (22282280).

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

20256580 is a wasteful number, since it uses less digits than its factorization.

20256580 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1012838 (or 1012836 counting only the distinct ones).

The product of its (nonzero) digits is 4800, while the sum is 28.

The square root of 20256580 is about 4500.7310517293. The cubic root of 20256580 is about 272.5976083290.

The spelling of 20256580 in words is "twenty million, two hundred fifty-six thousand, five hundred eighty".