811097840 has 80 divisors (see below), whose sum is σ = 2268664320. Its totient is φ = 263450880.

The previous prime is 811097759. The next prime is 811097843. The reversal of 811097840 is 48790118.

It is a tau number, because it is divible by the number of its divisors (80).

It is a Harshad number since it is a multiple of its sum of digits (38).

It is a junction number, because it is equal to n+sod(n) for n = 811097794 and 811097803.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (811097843) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 27476 + ... + 48755.

It is an arithmetic number, because the mean of its divisors is an integer number (28358304).

Almost surely, 2^811097840 is an apocalyptic number.

811097840 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

811097840 is an abundant number, since it is smaller than the sum of its proper divisors (1457566480).

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

811097840 is a wasteful number, since it uses less digits than its factorization.

811097840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 76270 (or 76264 counting only the distinct ones).

The product of its (nonzero) digits is 16128, while the sum is 38.

The square root of 811097840 is about 28479.7794935284. The cubic root of 811097840 is about 932.5907029147.

The spelling of 811097840 in words is "eight hundred eleven million, ninety-seven thousand, eight hundred forty".