72221837 has 2 divisors, whose sum is σ = 72221838. Its totient is φ = 72221836.

The previous prime is 72221833. The next prime is 72221873. The reversal of 72221837 is 73812227.

Together with next prime (72221873) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 39262756 + 32959081 = 6266^2 + 5741^2 .

It is an emirp because it is prime and its reverse (73812227) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 72221837 - 2² = 72221833 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (72221833) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36110918 + 36110919.

It is an arithmetic number, because the mean of its divisors is an integer number (36110919).

Almost surely, 2^72221837 is an apocalyptic number.

It is an amenable number.

72221837 is a deficient number, since it is larger than the sum of its proper divisors (1).

72221837 is an equidigital number, since it uses as much as digits as its factorization.

72221837 is an evil number, because the sum of its binary digits is even.

The product of its digits is 9408, while the sum is 32.

The square root of 72221837 is about 8498.3431914697. The cubic root of 72221837 is about 416.4435854025.

The spelling of 72221837 in words is "seventy-two million, two hundred twenty-one thousand, eight hundred thirty-seven".