213121313021117 has 2 divisors, whose sum is σ = 213121313021118. Its totient is φ = 213121313021116.

The previous prime is 213121313021077. The next prime is 213121313021129. The reversal of 213121313021117 is 711120313121312.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 141834260917561 + 71287052103556 = 11909419^2 + 8443166^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-213121313021117 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 213121313021117.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (213123313021117) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 106560656510558 + 106560656510559.

It is an arithmetic number, because the mean of its divisors is an integer number (106560656510559).

Almost surely, 2^{213121313021117} is an apocalyptic number.

It is an amenable number.

213121313021117 is a deficient number, since it is larger than the sum of its proper divisors (1).

213121313021117 is an equidigital number, since it uses as much as digits as its factorization.

213121313021117 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1512, while the sum is 29.

Adding to 213121313021117 its reverse (711120313121312), we get a palindrome (924241626142429).

The spelling of 213121313021117 in words is "two hundred thirteen trillion, one hundred twenty-one billion, three hundred thirteen million, twenty-one thousand, one hundred seventeen".