816390819 has 72 divisors (see below), whose sum is σ = 1322979840. Its totient is φ = 502053552.

The previous prime is 816390787. The next prime is 816390833. The reversal of 816390819 is 918093618.

816390819 is a `hidden beast` number, since 8 + 1 + 639 + 0 + 8 + 1 + 9 = 666.

Together with 506589020 it forms a betrothed pair.

It is not a de Polignac number, because 816390819 - 2⁵ = 816390787 is a prime.

It is a super-2 number, since 2×816390819² = 1332987938694981522, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (816390889) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 10334022 + ... + 10334100.

It is an arithmetic number, because the mean of its divisors is an integer number (18374720).

Almost surely, 2^816390819 is an apocalyptic number.

816390819 is a deficient number, since it is larger than the sum of its proper divisors (506589021).

816390819 is an equidigital number, since it uses as much as digits as its factorization.

816390819 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 203 (or 148 counting only the distinct ones).

The product of its (nonzero) digits is 93312, while the sum is 45.

The square root of 816390819 is about 28572.5535960649. The cubic root of 816390819 is about 934.6149077132.

The spelling of 816390819 in words is "eight hundred sixteen million, three hundred ninety thousand, eight hundred nineteen".