72180397 has 2 divisors, whose sum is σ = 72180398. Its totient is φ = 72180396.

The previous prime is 72180389. The next prime is 72180403. The reversal of 72180397 is 79308127.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 63776196 + 8404201 = 7986^2 + 2899^2 .

It is a cyclic number.

It is not a de Polignac number, because 72180397 - 2³ = 72180389 is a prime.

It is a super-2 number, since 2×72180397² = 10420019422155218, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (72180197) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36090198 + 36090199.

It is an arithmetic number, because the mean of its divisors is an integer number (36090199).

Almost surely, 2^72180397 is an apocalyptic number.

It is an amenable number.

72180397 is a deficient number, since it is larger than the sum of its proper divisors (1).

72180397 is an equidigital number, since it uses as much as digits as its factorization.

72180397 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 21168, while the sum is 37.

The square root of 72180397 is about 8495.9047193339. The cubic root of 72180397 is about 416.3639200979.

It can be divided in two parts, 721 and 80397, that added together give a palindrome (81118).

The spelling of 72180397 in words is "seventy-two million, one hundred eighty thousand, three hundred ninety-seven".