72397861 has 2 divisors, whose sum is σ = 72397862. Its totient is φ = 72397860.

The previous prime is 72397811. The next prime is 72397867. The reversal of 72397861 is 16879327.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 58752225 + 13645636 = 7665^2 + 3694^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-72397861 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (72397867) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36198930 + 36198931.

It is an arithmetic number, because the mean of its divisors is an integer number (36198931).

Almost surely, 2^72397861 is an apocalyptic number.

It is an amenable number.

72397861 is a deficient number, since it is larger than the sum of its proper divisors (1).

72397861 is an equidigital number, since it uses as much as digits as its factorization.

72397861 is an evil number, because the sum of its binary digits is even.

The product of its digits is 127008, while the sum is 43.

The square root of 72397861 is about 8508.6932604249. The cubic root of 72397861 is about 416.7816391700.

The spelling of 72397861 in words is "seventy-two million, three hundred ninety-seven thousand, eight hundred sixty-one".