211561055 has 4 divisors (see below), whose sum is σ = 253873272. Its totient is φ = 169248840.

The previous prime is 211561033. The next prime is 211561093. The reversal of 211561055 is 550165112.

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

It is not a de Polignac number, because 211561055 - 2⁸ = 211560799 is a prime.

It is a Duffinian number.

It is a congruent 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, 21156101 + ... + 21156110.

It is an arithmetic number, because the mean of its divisors is an integer number (63468318).

Almost surely, 2^211561055 is an apocalyptic number.

211561055 is a deficient number, since it is larger than the sum of its proper divisors (42312217).

211561055 is an equidigital number, since it uses as much as digits as its factorization.

211561055 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42312216.

The product of its (nonzero) digits is 1500, while the sum is 26.

The square root of 211561055 is about 14545.1385349195. The cubic root of 211561055 is about 595.8613844793.

The spelling of 211561055 in words is "two hundred eleven million, five hundred sixty-one thousand, fifty-five".