212194921 has 2 divisors, whose sum is σ = 212194922. Its totient is φ = 212194920.

The previous prime is 212194891. The next prime is 212194937. The reversal of 212194921 is 129491212.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 212139225 + 55696 = 14565^2 + 236^2 .

It is a cyclic number.

It is not a de Polignac number, because 212194921 - 2¹¹ = 212192873 is a prime.

It is not a weakly prime, because it can be changed into another prime (212164921) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 106097460 + 106097461.

It is an arithmetic number, because the mean of its divisors is an integer number (106097461).

Almost surely, 2^212194921 is an apocalyptic number.

It is an amenable number.

212194921 is a deficient number, since it is larger than the sum of its proper divisors (1).

212194921 is an equidigital number, since it uses as much as digits as its factorization.

212194921 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2592, while the sum is 31.

The square root of 212194921 is about 14566.9118552973. The cubic root of 212194921 is about 596.4558853417.

The spelling of 212194921 in words is "two hundred twelve million, one hundred ninety-four thousand, nine hundred twenty-one".