72289961 has 2 divisors, whose sum is σ = 72289962. Its totient is φ = 72289960.

The previous prime is 72289951. The next prime is 72289963. The reversal of 72289961 is 16998227.

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., 58369600 + 13920361 = 7640^2 + 3731^2 .

It is an emirp because it is prime and its reverse (16998227) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-72289961 is a prime.

It is a super-3 number, since 3×72289961³ (a number of 25 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

Together with 72289963, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (72289963) 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, 36144980 + 36144981.

It is an arithmetic number, because the mean of its divisors is an integer number (36144981).

Almost surely, 2^72289961 is an apocalyptic number.

It is an amenable number.

72289961 is a deficient number, since it is larger than the sum of its proper divisors (1).

72289961 is an equidigital number, since it uses as much as digits as its factorization.

72289961 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 108864, while the sum is 44.

The square root of 72289961 is about 8502.3503221168. The cubic root of 72289961 is about 416.5744825043.

The spelling of 72289961 in words is "seventy-two million, two hundred eighty-nine thousand, nine hundred sixty-one".