213713266721 has 2 divisors, whose sum is σ = 213713266722. Its totient is φ = 213713266720.

The previous prime is 213713266717. The next prime is 213713266751. The reversal of 213713266721 is 127662317312.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 174088383121 + 39624883600 = 417239^2 + 199060^2 .

It is a cyclic number.

It is not a de Polignac number, because 213713266721 - 2² = 213713266717 is a prime.

It is a super-2 number, since 2×213713266721² (a number of 23 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (213713266751) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 106856633360 + 106856633361.

It is an arithmetic number, because the mean of its divisors is an integer number (106856633361).

Almost surely, 2^213713266721 is an apocalyptic number.

It is an amenable number.

213713266721 is a deficient number, since it is larger than the sum of its proper divisors (1).

213713266721 is an equidigital number, since it uses as much as digits as its factorization.

213713266721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 127008, while the sum is 41.

The spelling of 213713266721 in words is "two hundred thirteen billion, seven hundred thirteen million, two hundred sixty-six thousand, seven hundred twenty-one".