211216491 has 40 divisors (see below), whose sum is σ = 323825040. Its totient is φ = 137161728.

The previous prime is 211216459. The next prime is 211216493. The reversal of 211216491 is 194612112.

211216491 is a `hidden beast` number, since 2 + 1 + 12 + 1 + 649 + 1 = 666.

It is not a de Polignac number, because 211216491 - 2⁵ = 211216459 is a prime.

It is a super-2 number, since 2×211216491² = 89224812140706162, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (211216493) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 598171 + ... + 598523.

It is an arithmetic number, because the mean of its divisors is an integer number (8095626).

Almost surely, 2^211216491 is an apocalyptic number.

211216491 is a deficient number, since it is larger than the sum of its proper divisors (112608549).

211216491 is an equidigital number, since it uses as much as digits as its factorization.

211216491 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 537 (or 528 counting only the distinct ones).

The product of its digits is 864, while the sum is 27.

The square root of 211216491 is about 14533.2890633882. The cubic root of 211216491 is about 595.5377207102.

The spelling of 211216491 in words is "two hundred eleven million, two hundred sixteen thousand, four hundred ninety-one".