72840769 has 2 divisors, whose sum is σ = 72840770. Its totient is φ = 72840768.

The previous prime is 72840707. The next prime is 72840791. The reversal of 72840769 is 96704827.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 52707600 + 20133169 = 7260^2 + 4487^2 .

It is an emirp because it is prime and its reverse (96704827) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 72840769 - 2¹⁹ = 72316481 is a prime.

It is a super-2 number, since 2×72840769² = 10611555257022722, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (72847769) 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, 36420384 + 36420385.

It is an arithmetic number, because the mean of its divisors is an integer number (36420385).

Almost surely, 2^72840769 is an apocalyptic number.

72840769 is the 4928-th hex number.

It is an amenable number.

72840769 is a deficient number, since it is larger than the sum of its proper divisors (1).

72840769 is an equidigital number, since it uses as much as digits as its factorization.

72840769 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 169344, while the sum is 43.

The square root of 72840769 is about 8534.6803689418. The cubic root of 72840769 is about 417.6298261195.

The spelling of 72840769 in words is "seventy-two million, eight hundred forty thousand, seven hundred sixty-nine".