812407640 has 96 divisors (see below), whose sum is σ = 2025157680. Its totient is φ = 290880000.

The previous prime is 812407621. The next prime is 812407649. The reversal of 812407640 is 46704218.

It is a junction number, because it is equal to n+sod(n) for n = 812407597 and 812407606.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (812407649) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 4488350 + ... + 4488530.

Almost surely, 2^812407640 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 812407640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1012578840).

812407640 is an abundant number, since it is smaller than the sum of its proper divisors (1212750040).

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

812407640 is a wasteful number, since it uses less digits than its factorization.

812407640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 405 (or 300 counting only the distinct ones).

The product of its (nonzero) digits is 10752, while the sum is 32.

The square root of 812407640 is about 28502.7654798618. The cubic root of 812407640 is about 933.0924304562.

The spelling of 812407640 in words is "eight hundred twelve million, four hundred seven thousand, six hundred forty".