72330821 has 2 divisors, whose sum is σ = 72330822. Its totient is φ = 72330820.

The previous prime is 72330799. The next prime is 72330827. The reversal of 72330821 is 12803327.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 65772100 + 6558721 = 8110^2 + 2561^2 .

It is an emirp because it is prime and its reverse (12803327) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 72330821 - 2¹⁰ = 72329797 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (72330827) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36165410 + 36165411.

It is an arithmetic number, because the mean of its divisors is an integer number (36165411).

Almost surely, 2^72330821 is an apocalyptic number.

It is an amenable number.

72330821 is a deficient number, since it is larger than the sum of its proper divisors (1).

72330821 is an equidigital number, since it uses as much as digits as its factorization.

72330821 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2016, while the sum is 26.

The square root of 72330821 is about 8504.7528476729. The cubic root of 72330821 is about 416.6529536465.

The spelling of 72330821 in words is "seventy-two million, three hundred thirty thousand, eight hundred twenty-one".