15131778816 has 432 divisors, whose sum is σ = 52093939968. Its totient is φ = 3785932800.

The previous prime is 15131778803. The next prime is 15131778817. The reversal of 15131778816 is 61887713151.

It is a super-3 number, since 3×15131778816³ (a number of 32 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (15131778817) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 191541465 + ... + 191541543.

It is an arithmetic number, because the mean of its divisors is an integer number (120587824).

Almost surely, 2^15131778816 is an apocalyptic number.

15131778816 is a gapful number since it is divisible by the number (16) 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 15131778816, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26046969984).

15131778816 is an abundant number, since it is smaller than the sum of its proper divisors (36962161152).

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

15131778816 is an equidigital number, since it uses as much as digits as its factorization.

15131778816 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 236 (or 143 counting only the distinct ones).

The product of its digits is 282240, while the sum is 48.

The spelling of 15131778816 in words is "fifteen billion, one hundred thirty-one million, seven hundred seventy-eight thousand, eight hundred sixteen".