816651810 has 48 divisors (see below), whose sum is σ = 2286628344. Its totient is φ = 201021696.

The previous prime is 816651809. The next prime is 816651833. The reversal of 816651810 is 18156618.

816651810 is a `hidden beast` number, since 81 + 66 + 518 + 1 + 0 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 222218649 + 594433161 = 14907^2 + 24381^2 .

It is a super-2 number, since 2×816651810² = 1333840357552552200, which contains 22 as substring.

It is a Curzon number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 347827 + ... + 350166.

Almost surely, 2^816651810 is an apocalyptic number.

816651810 is an abundant number, since it is smaller than the sum of its proper divisors (1469976534).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

816651810 is a wasteful number, since it uses less digits than its factorization.

816651810 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 698019 (or 698016 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 36.

The square root of 816651810 is about 28577.1203937696. The cubic root of 816651810 is about 934.7144924075.

The spelling of 816651810 in words is "eight hundred sixteen million, six hundred fifty-one thousand, eight hundred ten".