816177961 has 2 divisors, whose sum is σ = 816177962. Its totient is φ = 816177960.

The previous prime is 816177959. The next prime is 816177997. The reversal of 816177961 is 169771618.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 465739561 + 350438400 = 21581^2 + 18720^2 .

It is a cyclic number.

It is not a de Polignac number, because 816177961 - 2¹ = 816177959 is a prime.

It is a super-2 number, since 2×816177961² = 1332292928044235042, which contains 22 as substring.

Together with 816177959, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (816172961) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 408088980 + 408088981.

It is an arithmetic number, because the mean of its divisors is an integer number (408088981).

Almost surely, 2^816177961 is an apocalyptic number.

It is an amenable number.

816177961 is a deficient number, since it is larger than the sum of its proper divisors (1).

816177961 is an equidigital number, since it uses as much as digits as its factorization.

816177961 is an evil number, because the sum of its binary digits is even.

The product of its digits is 127008, while the sum is 46.

The square root of 816177961 is about 28568.8284849064. The cubic root of 816177961 is about 934.5336731101.

The spelling of 816177961 in words is "eight hundred sixteen million, one hundred seventy-seven thousand, nine hundred sixty-one".