20556427 has 4 divisors (see below), whose sum is σ = 20565496. Its totient is φ = 20547360.

The previous prime is 20556409. The next prime is 20556433. The reversal of 20556427 is 72465502.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 20556427 - 2⁷ = 20556299 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20556407) 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 3 ways as a sum of consecutive naturals, for example, 2227 + ... + 6787.

It is an arithmetic number, because the mean of its divisors is an integer number (5141374).

Almost surely, 2^20556427 is an apocalyptic number.

20556427 is a deficient number, since it is larger than the sum of its proper divisors (9069).

20556427 is an equidigital number, since it uses as much as digits as its factorization.

20556427 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9068.

The product of its (nonzero) digits is 16800, while the sum is 31.

The square root of 20556427 is about 4533.9196066979. The cubic root of 20556427 is about 273.9360631893.

The spelling of 20556427 in words is "twenty million, five hundred fifty-six thousand, four hundred twenty-seven".