72784881 has 24 divisors (see below), whose sum is σ = 115990056. Its totient is φ = 43695360.

The previous prime is 72784813. The next prime is 72784897. The reversal of 72784881 is 18848727.

It can be written as a sum of positive squares in 4 ways, for example, as 2073600 + 70711281 = 1440^2 + 8409^2 .

It is not a de Polignac number, because 72784881 - 2⁷ = 72784753 is a prime.

It is a super-2 number, since 2×72784881² = 10595277804368322, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (72784381) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2790 + ... + 12383.

It is an arithmetic number, because the mean of its divisors is an integer number (4832919).

Almost surely, 2^72784881 is an apocalyptic number.

It is an amenable number.

72784881 is a deficient number, since it is larger than the sum of its proper divisors (43205175).

72784881 is a wasteful number, since it uses less digits than its factorization.

72784881 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15233 (or 15230 counting only the distinct ones).

The product of its digits is 200704, while the sum is 45.

The square root of 72784881 is about 8531.4055700101. The cubic root of 72784881 is about 417.5229882044.

The spelling of 72784881 in words is "seventy-two million, seven hundred eighty-four thousand, eight hundred eighty-one".