72724397 has 2 divisors, whose sum is σ = 72724398. Its totient is φ = 72724396.

The previous prime is 72724387. The next prime is 72724409. The reversal of 72724397 is 79342727.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 70324996 + 2399401 = 8386^2 + 1549^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-72724397 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (72724387) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36362198 + 36362199.

It is an arithmetic number, because the mean of its divisors is an integer number (36362199).

Almost surely, 2^72724397 is an apocalyptic number.

It is an amenable number.

72724397 is a deficient number, since it is larger than the sum of its proper divisors (1).

72724397 is an equidigital number, since it uses as much as digits as its factorization.

72724397 is an evil number, because the sum of its binary digits is even.

The product of its digits is 148176, while the sum is 41.

The square root of 72724397 is about 8527.8600481012. The cubic root of 72724397 is about 417.4073027374.

The spelling of 72724397 in words is "seventy-two million, seven hundred twenty-four thousand, three hundred ninety-seven".