812005680 has 80 divisors (see below), whose sum is σ = 2665302624. Its totient is φ = 203796480.

The previous prime is 812005669. The next prime is 812005681. The reversal of 812005680 is 86500218.

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 (30).

It is not an unprimeable number, because it can be changed into a prime (812005681) 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, 95431 + ... + 103590.

Almost surely, 2^812005680 is an apocalyptic number.

812005680 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

812005680 is an abundant number, since it is smaller than the sum of its proper divisors (1853296944).

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

812005680 is a wasteful number, since it uses less digits than its factorization.

812005680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 199054 (or 199048 counting only the distinct ones).

The product of its (nonzero) digits is 3840, while the sum is 30.

The square root of 812005680 is about 28495.7133618374. The cubic root of 812005680 is about 932.9385144130.

Adding to 812005680 its reverse (86500218), we get a palindrome (898505898).

The spelling of 812005680 in words is "eight hundred twelve million, five thousand, six hundred eighty".