72784000081 has 8 divisors (see below), whose sum is σ = 79456506920. Its totient is φ = 66264884352.

The previous prime is 72784000061. The next prime is 72784000087. The reversal of 72784000081 is 18000048727.

It can be written as a sum of positive squares in 4 ways, for example, as 6112112400 + 66671887681 = 78180^2 + 258209^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 72784000081 - 2¹⁵ = 72783967313 is a prime.

It is a super-2 number, since 2×72784000081² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 72784000081.

It is not an unprimeable number, because it can be changed into a prime (72784000087) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 38346786 + ... + 38348683.

It is an arithmetic number, because the mean of its divisors is an integer number (9932063365).

Almost surely, 2^72784000081 is an apocalyptic number.

72784000081 is the 155761-st hex number.

It is an amenable number.

72784000081 is a deficient number, since it is larger than the sum of its proper divisors (6672506839).

72784000081 is a wasteful number, since it uses less digits than its factorization.

72784000081 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 76695555.

The product of its (nonzero) digits is 25088, while the sum is 37.

The spelling of 72784000081 in words is "seventy-two billion, seven hundred eighty-four million, eighty-one", and thus it is an aban number.