20155555 has 16 divisors (see below), whose sum is σ = 27915264. Its totient is φ = 13684320.

The previous prime is 20155547. The next prime is 20155571. The reversal of 20155555 is 55555102.

It is a happy number.

It is not a de Polignac number, because 20155555 - 2³ = 20155547 is a prime.

It is a Duffinian number.

20155555 is a modest number, since divided by 5555 gives 2015 as remainder.

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, 810 + ... + 6400.

It is an arithmetic number, because the mean of its divisors is an integer number (1744704).

Almost surely, 2^20155555 is an apocalyptic number.

20155555 is a deficient number, since it is larger than the sum of its proper divisors (7759709).

20155555 is a wasteful number, since it uses less digits than its factorization.

20155555 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5706.

The product of its (nonzero) digits is 6250, while the sum is 28.

The square root of 20155555 is about 4489.4938467493. The cubic root of 20155555 is about 272.1436803970.

The spelling of 20155555 in words is "twenty million, one hundred fifty-five thousand, five hundred fifty-five".