211505216 has 28 divisors (see below), whose sum is σ = 451992492. Its totient is φ = 97617408.

The previous prime is 211505179. The next prime is 211505221. The reversal of 211505216 is 612505112.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 127599616 + 83905600 = 11296^2 + 9160^2 .

It is a hoax number, since the sum of its digits (23) coincides with the sum of the digits of its distinct prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 211505191 and 211505200.

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, 126275 + ... + 127938.

It is an arithmetic number, because the mean of its divisors is an integer number (16142589).

Almost surely, 2^211505216 is an apocalyptic number.

211505216 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is an amenable number.

211505216 is an abundant number, since it is smaller than the sum of its proper divisors (240487276).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

211505216 is a wasteful number, since it uses less digits than its factorization.

211505216 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 254238 (or 254228 counting only the distinct ones).

The product of its (nonzero) digits is 600, while the sum is 23.

The square root of 211505216 is about 14543.2189009174. The cubic root of 211505216 is about 595.8089563807.

The spelling of 211505216 in words is "two hundred eleven million, five hundred five thousand, two hundred sixteen".