20556340 has 48 divisors (see below), whose sum is σ = 49593600. Its totient is φ = 7011072.

The previous prime is 20556307. The next prime is 20556391. The reversal of 20556340 is 4365502.

It is a super-2 number, since 2×20556340² = 845126228391200, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 50056 + ... + 50464.

It is an arithmetic number, because the mean of its divisors is an integer number (1033200).

Almost surely, 2^20556340 is an apocalyptic number.

20556340 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20556340 is an abundant number, since it is smaller than the sum of its proper divisors (29037260).

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

20556340 is a wasteful number, since it uses less digits than its factorization.

20556340 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 784 (or 782 counting only the distinct ones).

The product of its (nonzero) digits is 3600, while the sum is 25.

The square root of 20556340 is about 4533.9100123403. The cubic root of 20556340 is about 273.9356767332.

The spelling of 20556340 in words is "twenty million, five hundred fifty-six thousand, three hundred forty".