72738391 has 4 divisors (see below), whose sum is σ = 79350984. Its totient is φ = 66125800.

The previous prime is 72738389. The next prime is 72738433. The reversal of 72738391 is 19383727.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 19383727 = 11 ⋅1762157.

It is a cyclic number.

It is not a de Polignac number, because 72738391 - 2¹ = 72738389 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72738301) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3306280 + ... + 3306301.

It is an arithmetic number, because the mean of its divisors is an integer number (19837746).

Almost surely, 2^72738391 is an apocalyptic number.

72738391 is a deficient number, since it is larger than the sum of its proper divisors (6612593).

72738391 is a wasteful number, since it uses less digits than its factorization.

72738391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6612592.

The product of its digits is 63504, while the sum is 40.

The square root of 72738391 is about 8528.6804958329. The cubic root of 72738391 is about 417.4340742356.

The spelling of 72738391 in words is "seventy-two million, seven hundred thirty-eight thousand, three hundred ninety-one".