813947880816 has 320 divisors, whose sum is σ = 2764023091200. Its totient is φ = 224386412544.

The previous prime is 813947880791. The next prime is 813947880833. The reversal of 813947880816 is 618088749318.

813947880816 is a `hidden beast` number, since 8 + 1 + 3 + 9 + 478 + 80 + 81 + 6 = 666.

It is a super-2 number, since 2×813947880816² (a number of 25 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 214590216 + ... + 214594008.

It is an arithmetic number, because the mean of its divisors is an integer number (8637572160).

Almost surely, 2^813947880816 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 813947880816, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1382011545600).

813947880816 is an abundant number, since it is smaller than the sum of its proper divisors (1950075210384).

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

813947880816 is a wasteful number, since it uses less digits than its factorization.

813947880816 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6293 (or 6281 counting only the distinct ones).

The product of its (nonzero) digits is 18579456, while the sum is 63.

The spelling of 813947880816 in words is "eight hundred thirteen billion, nine hundred forty-seven million, eight hundred eighty thousand, eight hundred sixteen".