916311821 has 2 divisors, whose sum is σ = 916311822. Its totient is φ = 916311820.

The previous prime is 916311749. The next prime is 916311839. The reversal of 916311821 is 128113619.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 887205796 + 29106025 = 29786^2 + 5395^2 .

It is a cyclic number.

It is not a de Polignac number, because 916311821 - 2¹⁴ = 916295437 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (916317821) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 458155910 + 458155911.

It is an arithmetic number, because the mean of its divisors is an integer number (458155911).

Almost surely, 2^916311821 is an apocalyptic number.

It is an amenable number.

916311821 is a deficient number, since it is larger than the sum of its proper divisors (1).

916311821 is an equidigital number, since it uses as much as digits as its factorization.

916311821 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2592, while the sum is 32.

The square root of 916311821 is about 30270.6428904310. The cubic root of 916311821 is about 971.2874183224.

The spelling of 916311821 in words is "nine hundred sixteen million, three hundred eleven thousand, eight hundred twenty-one".