72806389 has 2 divisors, whose sum is σ = 72806390. Its totient is φ = 72806388.

The previous prime is 72806381. The next prime is 72806411. The reversal of 72806389 is 98360827.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 36505764 + 36300625 = 6042^2 + 6025^2 .

It is a cyclic number.

It is not a de Polignac number, because 72806389 - 2³ = 72806381 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (72806381) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36403194 + 36403195.

It is an arithmetic number, because the mean of its divisors is an integer number (36403195).

Almost surely, 2^72806389 is an apocalyptic number.

It is an amenable number.

72806389 is a deficient number, since it is larger than the sum of its proper divisors (1).

72806389 is an equidigital number, since it uses as much as digits as its factorization.

72806389 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 145152, while the sum is 43.

The square root of 72806389 is about 8532.6659960413. The cubic root of 72806389 is about 417.5641102978.

The spelling of 72806389 in words is "seventy-two million, eight hundred six thousand, three hundred eighty-nine".