20556155 has 8 divisors (see below), whose sum is σ = 25192512. Its totient is φ = 16094848.

The previous prime is 20556149. The next prime is 20556161. The reversal of 20556155 is 55165502.

It is an interprime number because it is at equal distance from previous prime (20556149) and next prime (20556161).

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

It is a cyclic number.

It is not a de Polignac number, because 20556155 - 2¹⁶ = 20490619 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 43502 + ... + 43971.

It is an arithmetic number, because the mean of its divisors is an integer number (3149064).

Almost surely, 2^20556155 is an apocalyptic number.

20556155 is a deficient number, since it is larger than the sum of its proper divisors (4636357).

20556155 is an equidigital number, since it uses as much as digits as its factorization.

20556155 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 87525.

The product of its (nonzero) digits is 7500, while the sum is 29.

The square root of 20556155 is about 4533.8896104780. The cubic root of 20556155 is about 273.9348549550.

The spelling of 20556155 in words is "twenty million, five hundred fifty-six thousand, one hundred fifty-five".