15811316640 has 480 divisors, whose sum is σ = 67136065920. Its totient is φ = 3423430656.

The previous prime is 15811316593. The next prime is 15811316669. The reversal of 15811316640 is 4661311851.

It is a happy number.

15811316640 is a `hidden beast` number, since 1 + 5 + 8 + 1 + 1 + 3 + 1 + 6 + 640 = 666.

It is a tau number, because it is divible by the number of its divisors (480).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 15811316595 and 15811316604.

It is an unprimeable number.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 1719094 + ... + 1728266.

It is an arithmetic number, because the mean of its divisors is an integer number (139866804).

Almost surely, 2^15811316640 is an apocalyptic number.

15811316640 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 15811316640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33568032960).

15811316640 is an abundant number, since it is smaller than the sum of its proper divisors (51324749280).

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

15811316640 is a wasteful number, since it uses less digits than its factorization.

15811316640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9226 (or 9209 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 36.

The spelling of 15811316640 in words is "fifteen billion, eight hundred eleven million, three hundred sixteen thousand, six hundred forty".