211555345 has 16 divisors (see below), whose sum is σ = 256270608. Its totient is φ = 167650560.

The previous prime is 211555303. The next prime is 211555423. The reversal of 211555345 is 543555112.

211555345 = 66² + 67² + ... + 859².

It can be written as a sum of positive squares in 8 ways, for example, as 16785409 + 194769936 = 4097^2 + 13956^2 .

It is not a de Polignac number, because 211555345 - 2⁷ = 211555217 is a prime.

It is a Duffinian number.

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, 390775 + ... + 391315.

It is an arithmetic number, because the mean of its divisors is an integer number (16016913).

Almost surely, 2^211555345 is an apocalyptic number.

It is an amenable number.

211555345 is a deficient number, since it is larger than the sum of its proper divisors (44715263).

211555345 is a wasteful number, since it uses less digits than its factorization.

211555345 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1140.

The product of its digits is 15000, while the sum is 31.

The square root of 211555345 is about 14544.9422480806. The cubic root of 211555345 is about 595.8560236956.

The spelling of 211555345 in words is "two hundred eleven million, five hundred fifty-five thousand, three hundred forty-five".