813945440 has 96 divisors (see below), whose sum is σ = 2397475584. Its totient is φ = 253693440.

The previous prime is 813945439. The next prime is 813945479. The reversal of 813945440 is 44549318.

It is a junction number, because it is equal to n+sod(n) for n = 813945394 and 813945403.

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 15 ways as a sum of consecutive naturals, for example, 20714 + ... + 45353.

It is an arithmetic number, because the mean of its divisors is an integer number (24973704).

Almost surely, 2^813945440 is an apocalyptic number.

813945440 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

813945440 is an abundant number, since it is smaller than the sum of its proper divisors (1583530144).

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

813945440 is a wasteful number, since it uses less digits than its factorization.

813945440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 66100 (or 66092 counting only the distinct ones).

The product of its (nonzero) digits is 69120, while the sum is 38.

The square root of 813945440 is about 28529.7290558463. The cubic root of 813945440 is about 933.6808071297.

The spelling of 813945440 in words is "eight hundred thirteen million, nine hundred forty-five thousand, four hundred forty".