817994456400 has 120 divisors (see below), whose sum is σ = 2858518855584. Its totient is φ = 198301683200.

The previous prime is 817994456393. The next prime is 817994456401. The reversal of 817994456400 is 4654499718.

817994456400 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (120).

It is a super-2 number, since 2×817994456400² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (817994456401) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 30971439 + ... + 30997838.

Almost surely, 2^817994456400 is an apocalyptic number.

817994456400 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

817994456400 is an abundant number, since it is smaller than the sum of its proper divisors (2040524399184).

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

817994456400 is a wasteful number, since it uses less digits than its factorization.

817994456400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 61969309 (or 61969298 counting only the distinct ones).

The product of its (nonzero) digits is 8709120, while the sum is 57.

The spelling of 817994456400 in words is "eight hundred seventeen billion, nine hundred ninety-four million, four hundred fifty-six thousand, four hundred".