811612440 has 128 divisors (see below), whose sum is σ = 2711620800. Its totient is φ = 215930880.

The previous prime is 811612433. The next prime is 811612447. The reversal of 811612440 is 44216118.

It is a happy number.

811612440 is a `hidden beast` number, since 8 + 1 + 1 + 612 + 4 + 40 = 666.

It is an interprime number because it is at equal distance from previous prime (811612433) and next prime (811612447).

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (811612447) 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, 920800 + ... + 921680.

Almost surely, 2^811612440 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 811612440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1355810400).

811612440 is an abundant number, since it is smaller than the sum of its proper divisors (1900008360).

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

811612440 is a wasteful number, since it uses less digits than its factorization.

811612440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1754 (or 1744 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 27.

The square root of 811612440 is about 28488.8125410660. The cubic root of 811612440 is about 932.7878882171.

Adding to 811612440 its reverse (44216118), we get a palindrome (855828558).

The spelling of 811612440 in words is "eight hundred eleven million, six hundred twelve thousand, four hundred forty".