21752205155 has 4 divisors (see below), whose sum is σ = 26102646192. Its totient is φ = 17401764120.

The previous prime is 21752205113. The next prime is 21752205161. The reversal of 21752205155 is 55150225712.

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

It is not a de Polignac number, because 21752205155 - 2⁶ = 21752205091 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, 2175220511 + ... + 2175220520.

It is an arithmetic number, because the mean of its divisors is an integer number (6525661548).

Almost surely, 2^21752205155 is an apocalyptic number.

21752205155 is a deficient number, since it is larger than the sum of its proper divisors (4350441037).

21752205155 is an equidigital number, since it uses as much as digits as its factorization.

21752205155 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4350441036.

The product of its (nonzero) digits is 35000, while the sum is 35.

The spelling of 21752205155 in words is "twenty-one billion, seven hundred fifty-two million, two hundred five thousand, one hundred fifty-five".