213580721 has 2 divisors, whose sum is σ = 213580722. Its totient is φ = 213580720.

The previous prime is 213580651. The next prime is 213580723. The reversal of 213580721 is 127085312.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 136773025 + 76807696 = 11695^2 + 8764^2 .

It is a cyclic number.

It is not a de Polignac number, because 213580721 - 2¹⁰ = 213579697 is a prime.

It is a Sophie Germain prime.

Together with 213580723, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (213580723) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 106790360 + 106790361.

It is an arithmetic number, because the mean of its divisors is an integer number (106790361).

Almost surely, 2^213580721 is an apocalyptic number.

It is an amenable number.

213580721 is a deficient number, since it is larger than the sum of its proper divisors (1).

213580721 is an equidigital number, since it uses as much as digits as its factorization.

213580721 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3360, while the sum is 29.

The square root of 213580721 is about 14614.4011509196. The cubic root of 213580721 is about 597.7515112077.

The spelling of 213580721 in words is "two hundred thirteen million, five hundred eighty thousand, seven hundred twenty-one".