72197813 has 2 divisors, whose sum is σ = 72197814. Its totient is φ = 72197812.

The previous prime is 72197789. The next prime is 72197821. The reversal of 72197813 is 31879127.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 64673764 + 7524049 = 8042^2 + 2743^2 .

It is a cyclic number.

It is not a de Polignac number, because 72197813 - 2¹² = 72193717 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (72197833) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36098906 + 36098907.

It is an arithmetic number, because the mean of its divisors is an integer number (36098907).

Almost surely, 2^72197813 is an apocalyptic number.

It is an amenable number.

72197813 is a deficient number, since it is larger than the sum of its proper divisors (1).

72197813 is an equidigital number, since it uses as much as digits as its factorization.

72197813 is an evil number, because the sum of its binary digits is even.

The product of its digits is 21168, while the sum is 38.

The square root of 72197813 is about 8496.9296219281. The cubic root of 72197813 is about 416.3974047705.

The spelling of 72197813 in words is "seventy-two million, one hundred ninety-seven thousand, eight hundred thirteen".