816990457 has 2 divisors, whose sum is σ = 816990458. Its totient is φ = 816990456.

The previous prime is 816990439. The next prime is 816990463. The reversal of 816990457 is 754099618.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 812022016 + 4968441 = 28496^2 + 2229^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-816990457 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 816990457.

It is not a weakly prime, because it can be changed into another prime (816990487) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 408495228 + 408495229.

It is an arithmetic number, because the mean of its divisors is an integer number (408495229).

Almost surely, 2^816990457 is an apocalyptic number.

It is an amenable number.

816990457 is a deficient number, since it is larger than the sum of its proper divisors (1).

816990457 is an equidigital number, since it uses as much as digits as its factorization.

816990457 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 544320, while the sum is 49.

The square root of 816990457 is about 28583.0449217714. The cubic root of 816990457 is about 934.8436761923.

The spelling of 816990457 in words is "eight hundred sixteen million, nine hundred ninety thousand, four hundred fifty-seven".