816406784 has 18 divisors (see below), whose sum is σ = 1629624990. Its totient is φ = 408203264.

The previous prime is 816406769. The next prime is 816406817. The reversal of 816406784 is 487604618.

It can be written as a sum of positive squares in only one way, i.e., 813846784 + 2560000 = 28528^2 + 1600^2 .

It is a super-2 number, since 2×816406784² = 1333040073922445312, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1594289 + ... + 1594800.

Almost surely, 2^816406784 is an apocalyptic number.

It is an amenable number.

816406784 is a deficient number, since it is larger than the sum of its proper divisors (813218206).

816406784 is an equidigital number, since it uses as much as digits as its factorization.

816406784 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3189105 (or 3189091 counting only the distinct ones).

The product of its (nonzero) digits is 258048, while the sum is 44.

The square root of 816406784 is about 28572.8329711984. The cubic root of 816406784 is about 934.6209999872.

The spelling of 816406784 in words is "eight hundred sixteen million, four hundred six thousand, seven hundred eighty-four".