212990917 has 4 divisors (see below), whose sum is σ = 213025356. Its totient is φ = 212956480.

The previous prime is 212990891. The next prime is 212990927. The reversal of 212990917 is 719099212.

It is a happy number.

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

It can be written as a sum of positive squares in 2 ways, for example, as 76895361 + 136095556 = 8769^2 + 11666^2 .

It is a cyclic number.

It is not a de Polignac number, because 212990917 - 2¹⁵ = 212958149 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 212990917.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (212990927) by changing a digit.

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, 5098 + ... + 21259.

It is an arithmetic number, because the mean of its divisors is an integer number (53256339).

Almost surely, 2^212990917 is an apocalyptic number.

It is an amenable number.

212990917 is a deficient number, since it is larger than the sum of its proper divisors (34439).

212990917 is an equidigital number, since it uses as much as digits as its factorization.

212990917 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34438.

The product of its (nonzero) digits is 20412, while the sum is 40.

The square root of 212990917 is about 14594.2083375564. The cubic root of 212990917 is about 597.2007728921.

The spelling of 212990917 in words is "two hundred twelve million, nine hundred ninety thousand, nine hundred seventeen".