212390669 has 2 divisors, whose sum is σ = 212390670. Its totient is φ = 212390668.

The previous prime is 212390657. The next prime is 212390677. The reversal of 212390669 is 966093212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 138344644 + 74046025 = 11762^2 + 8605^2 .

It is a cyclic number.

It is not a de Polignac number, because 212390669 - 2²⁰ = 211342093 is a prime.

It is a super-2 number, since 2×212390669² = 90219592556535122, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (212390369) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 106195334 + 106195335.

It is an arithmetic number, because the mean of its divisors is an integer number (106195335).

Almost surely, 2^212390669 is an apocalyptic number.

It is an amenable number.

212390669 is a deficient number, since it is larger than the sum of its proper divisors (1).

212390669 is an equidigital number, since it uses as much as digits as its factorization.

212390669 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 34992, while the sum is 38.

The square root of 212390669 is about 14573.6292322812. The cubic root of 212390669 is about 596.6392374575.

The spelling of 212390669 in words is "two hundred twelve million, three hundred ninety thousand, six hundred sixty-nine".