213918961 has 2 divisors, whose sum is σ = 213918962. Its totient is φ = 213918960.

The previous prime is 213918923. The next prime is 213918979. The reversal of 213918961 is 169819312.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 206928225 + 6990736 = 14385^2 + 2644^2 .

It is a cyclic number.

It is not a de Polignac number, because 213918961 - 2¹³ = 213910769 is a prime.

It is a super-2 number, since 2×213918961² = 91522643750639042, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (213918161) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 106959480 + 106959481.

It is an arithmetic number, because the mean of its divisors is an integer number (106959481).

Almost surely, 2^213918961 is an apocalyptic number.

It is an amenable number.

213918961 is a deficient number, since it is larger than the sum of its proper divisors (1).

213918961 is an equidigital number, since it uses as much as digits as its factorization.

213918961 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 23328, while the sum is 40.

The square root of 213918961 is about 14625.9687200541. The cubic root of 213918961 is about 598.0668905388.

The spelling of 213918961 in words is "two hundred thirteen million, nine hundred eighteen thousand, nine hundred sixty-one".