72427321 has 4 divisors (see below), whose sum is σ = 72488052. Its totient is φ = 72366592.

The previous prime is 72427291. The next prime is 72427357. The reversal of 72427321 is 12372427.

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

It can be written as a sum of positive squares in 2 ways, for example, as 6817321 + 65610000 = 2611^2 + 8100^2 .

It is a cyclic number.

It is not a de Polignac number, because 72427321 - 2⁷ = 72427193 is a prime.

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 72427321.

It is not an unprimeable number, because it can be changed into a prime (72427721) 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, 28540 + ... + 30973.

It is an arithmetic number, because the mean of its divisors is an integer number (18122013).

Almost surely, 2^72427321 is an apocalyptic number.

It is an amenable number.

72427321 is a deficient number, since it is larger than the sum of its proper divisors (60731).

72427321 is a wasteful number, since it uses less digits than its factorization.

72427321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 60730.

The product of its digits is 4704, while the sum is 28.

The square root of 72427321 is about 8510.4242549946. The cubic root of 72427321 is about 416.8381635013.

Adding to 72427321 its reverse (12372427), we get a palindrome (84799748).

The spelling of 72427321 in words is "seventy-two million, four hundred twenty-seven thousand, three hundred twenty-one".