72216013 has 2 divisors, whose sum is σ = 72216014. Its totient is φ = 72216012.

The previous prime is 72215999. The next prime is 72216029. The reversal of 72216013 is 31061227.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 72216004 + 9 = 8498^2 + 3^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-72216013 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (72216043) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36108006 + 36108007.

It is an arithmetic number, because the mean of its divisors is an integer number (36108007).

Almost surely, 2^72216013 is an apocalyptic number.

It is an amenable number.

72216013 is a deficient number, since it is larger than the sum of its proper divisors (1).

72216013 is an equidigital number, since it uses as much as digits as its factorization.

72216013 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 504, while the sum is 22.

The square root of 72216013 is about 8498.0005295363. Note that the first 3 decimals coincide. The cubic root of 72216013 is about 416.4323910383.

The spelling of 72216013 in words is "seventy-two million, two hundred sixteen thousand, thirteen".