20555505155 has 4 divisors (see below), whose sum is σ = 24666606192. Its totient is φ = 16444404120.

The previous prime is 20555505121. The next prime is 20555505169. The reversal of 20555505155 is 55150555502.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 20555505155 - 2¹⁰ = 20555504131 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2055550511 + ... + 2055550520.

It is an arithmetic number, because the mean of its divisors is an integer number (6166651548).

Almost surely, 2^20555505155 is an apocalyptic number.

20555505155 is a deficient number, since it is larger than the sum of its proper divisors (4111101037).

20555505155 is an equidigital number, since it uses as much as digits as its factorization.

20555505155 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4111101036.

The product of its (nonzero) digits is 156250, while the sum is 38.

The spelling of 20555505155 in words is "twenty billion, five hundred fifty-five million, five hundred five thousand, one hundred fifty-five".