72018431 has 4 divisors (see below), whose sum is σ = 72138864. Its totient is φ = 71898000.

The previous prime is 72018413. The next prime is 72018433. The reversal of 72018431 is 13481027.

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 72018431 - 2¹⁸ = 71756287 is a prime.

It is a super-2 number, since 2×72018431² = 10373308807403522, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 72018431.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72018433) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 59315 + ... + 60516.

It is an arithmetic number, because the mean of its divisors is an integer number (18034716).

Almost surely, 2^72018431 is an apocalyptic number.

72018431 is a deficient number, since it is larger than the sum of its proper divisors (120433).

72018431 is a wasteful number, since it uses less digits than its factorization.

72018431 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 120432.

The product of its (nonzero) digits is 1344, while the sum is 26.

The square root of 72018431 is about 8486.3673618339. The cubic root of 72018431 is about 416.0522597530.

Adding to 72018431 its reverse (13481027), we get a palindrome (85499458).

The spelling of 72018431 in words is "seventy-two million, eighteen thousand, four hundred thirty-one".