13817999520 has 384 divisors, whose sum is σ = 53770106880. Its totient is φ = 3291217920.

The previous prime is 13817999473. The next prime is 13817999549. The reversal of 13817999520 is 2599971831.

13817999520 is a `hidden beast` number, since 13 + 8 + 17 + 9 + 99 + 520 = 666.

It is a super-2 number, since 2×13817999520² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1736992 + ... + 1744928.

It is an arithmetic number, because the mean of its divisors is an integer number (140026320).

Almost surely, 2^13817999520 is an apocalyptic number.

13817999520 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 13817999520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26885053440).

13817999520 is an abundant number, since it is smaller than the sum of its proper divisors (39952107360).

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

13817999520 is a wasteful number, since it uses less digits than its factorization.

13817999520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8005 (or 7991 counting only the distinct ones).

The product of its (nonzero) digits is 1224720, while the sum is 54.

The spelling of 13817999520 in words is "thirteen billion, eight hundred seventeen million, nine hundred ninety-nine thousand, five hundred twenty".