716891221 has 2 divisors, whose sum is σ = 716891222. Its totient is φ = 716891220.

The previous prime is 716891183. The next prime is 716891297. The reversal of 716891221 is 122198617.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 698280625 + 18610596 = 26425^2 + 4314^2 .

It is a cyclic number.

It is not a de Polignac number, because 716891221 - 2⁹ = 716890709 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (716891321) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 358445610 + 358445611.

It is an arithmetic number, because the mean of its divisors is an integer number (358445611).

Almost surely, 2^716891221 is an apocalyptic number.

It is an amenable number.

716891221 is a deficient number, since it is larger than the sum of its proper divisors (1).

716891221 is an equidigital number, since it uses as much as digits as its factorization.

716891221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 12096, while the sum is 37.

The square root of 716891221 is about 26774.8243878461. The cubic root of 716891221 is about 894.9891163122.

It can be divided in two parts, 7168 and 91221, that added together give a palindrome (98389).

The spelling of 716891221 in words is "seven hundred sixteen million, eight hundred ninety-one thousand, two hundred twenty-one".