816177997 has 2 divisors, whose sum is σ = 816177998. Its totient is φ = 816177996.

The previous prime is 816177961. The next prime is 816178039. The reversal of 816177997 is 799771618.

816177997 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 547840836 + 268337161 = 23406^2 + 16381^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-816177997 is a prime.

It is a super-2 number, since 2×816177997² = 1332293045573864018, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (816177907) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 408088998 + 408088999.

It is an arithmetic number, because the mean of its divisors is an integer number (408088999).

Almost surely, 2^816177997 is an apocalyptic number.

It is an amenable number.

816177997 is a deficient number, since it is larger than the sum of its proper divisors (1).

816177997 is an equidigital number, since it uses as much as digits as its factorization.

816177997 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1333584, while the sum is 55.

The square root of 816177997 is about 28568.8291149637. The cubic root of 816177997 is about 934.5336868502.

The spelling of 816177997 in words is "eight hundred sixteen million, one hundred seventy-seven thousand, nine hundred ninety-seven".