72303991 has 2 divisors, whose sum is σ = 72303992. Its totient is φ = 72303990.

The previous prime is 72303983. The next prime is 72304061. The reversal of 72303991 is 19930327.

It is a weak prime.

It is an emirp because it is prime and its reverse (19930327) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 72303991 - 2³ = 72303983 is a prime.

It is a super-2 number, since 2×72303991² = 10455734229056162, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (72303961) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36151995 + 36151996.

It is an arithmetic number, because the mean of its divisors is an integer number (36151996).

Almost surely, 2^72303991 is an apocalyptic number.

72303991 is a deficient number, since it is larger than the sum of its proper divisors (1).

72303991 is an equidigital number, since it uses as much as digits as its factorization.

72303991 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 10206, while the sum is 34.

The square root of 72303991 is about 8503.1753480685. The cubic root of 72303991 is about 416.6014302844.

The spelling of 72303991 in words is "seventy-two million, three hundred three thousand, nine hundred ninety-one".