72308381 has 2 divisors, whose sum is σ = 72308382. Its totient is φ = 72308380.

The previous prime is 72308351. The next prime is 72308393. The reversal of 72308381 is 18380327.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 60295225 + 12013156 = 7765^2 + 3466^2 .

It is a cyclic number.

It is not a de Polignac number, because 72308381 - 2¹⁴ = 72291997 is a prime.

It is a super-2 number, since 2×72308381² = 10457003925682322, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (72308351) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36154190 + 36154191.

It is an arithmetic number, because the mean of its divisors is an integer number (36154191).

Almost surely, 2^72308381 is an apocalyptic number.

It is an amenable number.

72308381 is a deficient number, since it is larger than the sum of its proper divisors (1).

72308381 is an equidigital number, since it uses as much as digits as its factorization.

72308381 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8064, while the sum is 32.

The square root of 72308381 is about 8503.4334830114. The cubic root of 72308381 is about 416.6098615538.

The spelling of 72308381 in words is "seventy-two million, three hundred eight thousand, three hundred eighty-one".