812211840 has 256 divisors, whose sum is σ = 3138825600. Its totient is φ = 196853760.

The previous prime is 812211833. The next prime is 812211847. The reversal of 812211840 is 48112218.

It is an interprime number because it is at equal distance from previous prime (812211833) and next prime (812211847).

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (812211847) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 187944 + ... + 192216.

Almost surely, 2^812211840 is an apocalyptic number.

812211840 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 812211840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1569412800).

812211840 is an abundant number, since it is smaller than the sum of its proper divisors (2326613760).

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

812211840 is a wasteful number, since it uses less digits than its factorization.

812211840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4312 (or 4294 counting only the distinct ones).

The product of its (nonzero) digits is 1024, while the sum is 27.

The square root of 812211840 is about 28499.3305184525. The cubic root of 812211840 is about 933.0174622718.

The spelling of 812211840 in words is "eight hundred twelve million, two hundred eleven thousand, eight hundred forty".