811617840 has 160 divisors (see below), whose sum is σ = 3049804800. Its totient is φ = 196750080.

The previous prime is 811617839. The next prime is 811617841. The reversal of 811617840 is 48716118.

It is an interprime number because it is at equal distance from previous prime (811617839) and next prime (811617841).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 811617795 and 811617804.

It is not an unprimeable number, because it can be changed into a prime (811617841) 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, 6681 + ... + 40839.

It is an arithmetic number, because the mean of its divisors is an integer number (19061280).

Almost surely, 2^811617840 is an apocalyptic number.

811617840 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 811617840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1524902400).

811617840 is an abundant number, since it is smaller than the sum of its proper divisors (2238186960).

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

811617840 is a wasteful number, since it uses less digits than its factorization.

811617840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34192 (or 34180 counting only the distinct ones).

The product of its (nonzero) digits is 10752, while the sum is 36.

The square root of 811617840 is about 28488.9073149533. The cubic root of 811617840 is about 932.7899569563.

The spelling of 811617840 in words is "eight hundred eleven million, six hundred seventeen thousand, eight hundred forty".