81615145248 has 576 divisors, whose sum is σ = 302429417472. Its totient is φ = 20288378880.

The previous prime is 81615145243. The next prime is 81615145277. The reversal of 81615145248 is 84254151618.

81615145248 is a `hidden beast` number, since 8 + 1 + 6 + 151 + 452 + 48 = 666.

It is a super-2 number, since 2×81615145248² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (81615145243) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 42796711 + ... + 42798617.

It is an arithmetic number, because the mean of its divisors is an integer number (525051072).

Almost surely, 2^81615145248 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 81615145248, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (151214708736).

81615145248 is an abundant number, since it is smaller than the sum of its proper divisors (220814272224).

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

81615145248 is a wasteful number, since it uses less digits than its factorization.

81615145248 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2037 (or 2026 counting only the distinct ones).

The product of its digits is 307200, while the sum is 45.

The spelling of 81615145248 in words is "eighty-one billion, six hundred fifteen million, one hundred forty-five thousand, two hundred forty-eight".