72144391 has 4 divisors (see below), whose sum is σ = 78702984. Its totient is φ = 65585800.

The previous prime is 72144383. The next prime is 72144403. The reversal of 72144391 is 19344127.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 72144391 - 2³ = 72144383 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 (72144361) 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, 3279280 + ... + 3279301.

It is an arithmetic number, because the mean of its divisors is an integer number (19675746).

Almost surely, 2^72144391 is an apocalyptic number.

72144391 is a deficient number, since it is larger than the sum of its proper divisors (6558593).

72144391 is a wasteful number, since it uses less digits than its factorization.

72144391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6558592.

The product of its digits is 6048, while the sum is 31.

The square root of 72144391 is about 8493.7854340688. The cubic root of 72144391 is about 416.2946764926.

The spelling of 72144391 in words is "seventy-two million, one hundred forty-four thousand, three hundred ninety-one".