72781868 has 6 divisors (see below), whose sum is σ = 127368276. Its totient is φ = 36390932.

The previous prime is 72781861. The next prime is 72781889. The reversal of 72781868 is 86818727.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (72781861) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9097730 + ... + 9097737.

It is an arithmetic number, because the mean of its divisors is an integer number (21228046).

Almost surely, 2^72781868 is an apocalyptic number.

It is an amenable number.

72781868 is a deficient number, since it is larger than the sum of its proper divisors (54586408).

72781868 is a wasteful number, since it uses less digits than its factorization.

72781868 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18195471 (or 18195469 counting only the distinct ones).

The product of its digits is 301056, while the sum is 47.

The square root of 72781868 is about 8531.2289853221. The cubic root of 72781868 is about 417.5172268699.

The spelling of 72781868 in words is "seventy-two million, seven hundred eighty-one thousand, eight hundred sixty-eight".