72789221 has 2 divisors, whose sum is σ = 72789222. Its totient is φ = 72789220.

The previous prime is 72789191. The next prime is 72789251. The reversal of 72789221 is 12298727.

It is a balanced prime because it is at equal distance from previous prime (72789191) and next prime (72789251).

It can be written as a sum of positive squares in only one way, i.e., 61058596 + 11730625 = 7814^2 + 3425^2 .

It is a cyclic number.

It is not a de Polignac number, because 72789221 - 2²⁶ = 5680357 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (72789251) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36394610 + 36394611.

It is an arithmetic number, because the mean of its divisors is an integer number (36394611).

Almost surely, 2^72789221 is an apocalyptic number.

It is an amenable number.

72789221 is a deficient number, since it is larger than the sum of its proper divisors (1).

72789221 is an equidigital number, since it uses as much as digits as its factorization.

72789221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 28224, while the sum is 38.

The square root of 72789221 is about 8531.6599205547. The cubic root of 72789221 is about 417.5312866941.

The spelling of 72789221 in words is "seventy-two million, seven hundred eighty-nine thousand, two hundred twenty-one".