211221992 has 16 divisors (see below), whose sum is σ = 396657540. Its totient is φ = 105446656.

The previous prime is 211221979. The next prime is 211222019. The reversal of 211221992 is 299122112.

211221992 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 187854436 + 23367556 = 13706^2 + 4834^2 .

It is a super-2 number, since 2×211221992² = 89229459808896128, which contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 14993 + ... + 25440.

Almost surely, 2^211221992 is an apocalyptic number.

It is an amenable number.

211221992 is a deficient number, since it is larger than the sum of its proper divisors (185435548).

211221992 is a wasteful number, since it uses less digits than its factorization.

211221992 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41092 (or 41088 counting only the distinct ones).

The product of its digits is 1296, while the sum is 29.

The square root of 211221992 is about 14533.4783173196. The cubic root of 211221992 is about 595.5428907998.

The spelling of 211221992 in words is "two hundred eleven million, two hundred twenty-one thousand, nine hundred ninety-two".