72689381 has 2 divisors, whose sum is σ = 72689382. Its totient is φ = 72689380.

The previous prime is 72689359. The next prime is 72689413. The reversal of 72689381 is 18398627.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 54626881 + 18062500 = 7391^2 + 4250^2 .

It is a cyclic number.

It is not a de Polignac number, because 72689381 - 2⁶ = 72689317 is a prime.

It is a super-2 number, since 2×72689381² = 10567492220326322, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (72689081) 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, 36344690 + 36344691.

It is an arithmetic number, because the mean of its divisors is an integer number (36344691).

Almost surely, 2^72689381 is an apocalyptic number.

It is an amenable number.

72689381 is a deficient number, since it is larger than the sum of its proper divisors (1).

72689381 is an equidigital number, since it uses as much as digits as its factorization.

72689381 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 145152, while the sum is 44.

The square root of 72689381 is about 8525.8067653448. The cubic root of 72689381 is about 417.3402996356.

The spelling of 72689381 in words is "seventy-two million, six hundred eighty-nine thousand, three hundred eighty-one".