72781133 has 2 divisors, whose sum is σ = 72781134. Its totient is φ = 72781132.

The previous prime is 72781129. The next prime is 72781157. The reversal of 72781133 is 33118727.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 51868804 + 20912329 = 7202^2 + 4573^2 .

It is an emirp because it is prime and its reverse (33118727) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 72781133 - 2² = 72781129 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 72781133.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (72781103) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36390566 + 36390567.

It is an arithmetic number, because the mean of its divisors is an integer number (36390567).

Almost surely, 2^72781133 is an apocalyptic number.

It is an amenable number.

72781133 is a deficient number, since it is larger than the sum of its proper divisors (1).

72781133 is an equidigital number, since it uses as much as digits as its factorization.

72781133 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 7056, while the sum is 32.

The square root of 72781133 is about 8531.1859081842. The cubic root of 72781133 is about 417.5158214091.

The spelling of 72781133 in words is "seventy-two million, seven hundred eighty-one thousand, one hundred thirty-three".