72236421 has 8 divisors (see below), whose sum is σ = 107016960. Its totient is φ = 48157596.

The previous prime is 72236407. The next prime is 72236441. The reversal of 72236421 is 12463227.

72236421 is a `hidden beast` number, since 7 + 2 + 236 + 421 = 666.

It is not a de Polignac number, because 72236421 - 2²³ = 63847813 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27), and also a Moran number because the ratio is a prime number: 2675423 = 72236421 / (7 + 2 + 2 + 3 + 6 + 4 + 2 + 1).

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72236441) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1337685 + ... + 1337738.

It is an arithmetic number, because the mean of its divisors is an integer number (13377120).

Almost surely, 2^72236421 is an apocalyptic number.

It is an amenable number.

72236421 is a deficient number, since it is larger than the sum of its proper divisors (34780539).

72236421 is a wasteful number, since it uses less digits than its factorization.

72236421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2675432 (or 2675426 counting only the distinct ones).

The product of its digits is 4032, while the sum is 27.

The square root of 72236421 is about 8499.2011977597. The cubic root of 72236421 is about 416.4716148035.

Adding to 72236421 its reverse (12463227), we get a palindrome (84699648).

The spelling of 72236421 in words is "seventy-two million, two hundred thirty-six thousand, four hundred twenty-one".