217126934621 has 2 divisors, whose sum is σ = 217126934622. Its totient is φ = 217126934620.

The previous prime is 217126934593. The next prime is 217126934641. The reversal of 217126934621 is 126439621712.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 205400210521 + 11726724100 = 453211^2 + 108290^2 .

It is a cyclic number.

It is not a de Polignac number, because 217126934621 - 2²⁶ = 217059825757 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (217126934641) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108563467310 + 108563467311.

It is an arithmetic number, because the mean of its divisors is an integer number (108563467311).

Almost surely, 2^217126934621 is an apocalyptic number.

It is an amenable number.

217126934621 is a deficient number, since it is larger than the sum of its proper divisors (1).

217126934621 is an equidigital number, since it uses as much as digits as its factorization.

217126934621 is an evil number, because the sum of its binary digits is even.

The product of its digits is 217728, while the sum is 44.

The spelling of 217126934621 in words is "two hundred seventeen billion, one hundred twenty-six million, nine hundred thirty-four thousand, six hundred twenty-one".