810668640 has 48 divisors (see below), whose sum is σ = 2553607728. Its totient is φ = 216178176.

The previous prime is 810668629. The next prime is 810668653. The reversal of 810668640 is 46866018.

It is a tau number, because it is divible by the number of its divisors (48).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 843967 + ... + 844926.

It is an arithmetic number, because the mean of its divisors is an integer number (53200161).

Almost surely, 2^810668640 is an apocalyptic number.

810668640 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

810668640 is an abundant number, since it is smaller than the sum of its proper divisors (1742939088).

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

810668640 is a wasteful number, since it uses less digits than its factorization.

810668640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1688911 (or 1688903 counting only the distinct ones).

The product of its (nonzero) digits is 55296, while the sum is 39.

The square root of 810668640 is about 28472.2433257374. The cubic root of 810668640 is about 932.4261775301.

The spelling of 810668640 in words is "eight hundred ten million, six hundred sixty-eight thousand, six hundred forty".