20556123 has 8 divisors (see below), whose sum is σ = 31323648. Its totient is φ = 11746344.

The previous prime is 20556121. The next prime is 20556149. The reversal of 20556123 is 32165502.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 20556123 - 2¹ = 20556121 is a prime.

It is a super-2 number, since 2×20556123² = 845108385582258, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 20556093 and 20556102.

It is not an unprimeable number, because it can be changed into a prime (20556121) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 489411 + ... + 489452.

It is an arithmetic number, because the mean of its divisors is an integer number (3915456).

Almost surely, 2^20556123 is an apocalyptic number.

20556123 is a deficient number, since it is larger than the sum of its proper divisors (10767525).

20556123 is an equidigital number, since it uses as much as digits as its factorization.

20556123 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 978873.

The product of its (nonzero) digits is 1800, while the sum is 24.

The square root of 20556123 is about 4533.8860814979. The cubic root of 20556123 is about 273.9347128091.

The spelling of 20556123 in words is "twenty million, five hundred fifty-six thousand, one hundred twenty-three".