812187656 has 48 divisors (see below), whose sum is σ = 1761138240. Its totient is φ = 343981440.

The previous prime is 812187641. The next prime is 812187671. The reversal of 812187656 is 656781218.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (812187641) and next prime (812187671).

It is an alternating number because its digits alternate between even and odd.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 442661 + ... + 444491.

It is an arithmetic number, because the mean of its divisors is an integer number (36690380).

Almost surely, 2^812187656 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 812187656, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (880569120).

812187656 is an abundant number, since it is smaller than the sum of its proper divisors (948950584).

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

812187656 is a wasteful number, since it uses less digits than its factorization.

812187656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2022 (or 1929 counting only the distinct ones).

The product of its digits is 161280, while the sum is 44.

The square root of 812187656 is about 28498.9062246255. The cubic root of 812187656 is about 933.0082018313.

The spelling of 812187656 in words is "eight hundred twelve million, one hundred eighty-seven thousand, six hundred fifty-six".