213667691 has 2 divisors, whose sum is σ = 213667692. Its totient is φ = 213667690.

The previous prime is 213667661. The next prime is 213667759. The reversal of 213667691 is 196766312.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 213667691 - 2⁶ = 213667627 is a prime.

It is not a weakly prime, because it can be changed into another prime (213667661) 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 as a sum of consecutive naturals, namely, 106833845 + 106833846.

It is an arithmetic number, because the mean of its divisors is an integer number (106833846).

Almost surely, 2^213667691 is an apocalyptic number.

213667691 is a deficient number, since it is larger than the sum of its proper divisors (1).

213667691 is an equidigital number, since it uses as much as digits as its factorization.

213667691 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 81648, while the sum is 41.

The square root of 213667691 is about 14617.3763377701. The cubic root of 213667691 is about 597.8326349378.

The spelling of 213667691 in words is "two hundred thirteen million, six hundred sixty-seven thousand, six hundred ninety-one".