72861281 has 2 divisors, whose sum is σ = 72861282. Its totient is φ = 72861280.

The previous prime is 72861203. The next prime is 72861323. The reversal of 72861281 is 18216827.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 56010256 + 16851025 = 7484^2 + 4105^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-72861281 is a prime.

It is a super-2 number, since 2×72861281² = 10617532537921922, which contains 22 as substring.

It is equal to p_4276385 and since 72861281 and 4276385 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (72861781) 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, 36430640 + 36430641.

It is an arithmetic number, because the mean of its divisors is an integer number (36430641).

Almost surely, 2^72861281 is an apocalyptic number.

It is an amenable number.

72861281 is a deficient number, since it is larger than the sum of its proper divisors (1).

72861281 is an equidigital number, since it uses as much as digits as its factorization.

72861281 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 10752, while the sum is 35.

The square root of 72861281 is about 8535.8819696620. The cubic root of 72861281 is about 417.6690240355.

The spelling of 72861281 in words is "seventy-two million, eight hundred sixty-one thousand, two hundred eighty-one".