72521549 has 2 divisors, whose sum is σ = 72521550. Its totient is φ = 72521548.

The previous prime is 72521531. The next prime is 72521551. The reversal of 72521549 is 94512527.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 50665924 + 21855625 = 7118^2 + 4675^2 .

It is a cyclic number.

It is not a de Polignac number, because 72521549 - 2¹² = 72517453 is a prime.

Together with 72521551, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (72521569) 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, 36260774 + 36260775.

It is an arithmetic number, because the mean of its divisors is an integer number (36260775).

Almost surely, 2^72521549 is an apocalyptic number.

It is an amenable number.

72521549 is a deficient number, since it is larger than the sum of its proper divisors (1).

72521549 is an equidigital number, since it uses as much as digits as its factorization.

72521549 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 25200, while the sum is 35.

The square root of 72521549 is about 8515.9584898002. The cubic root of 72521549 is about 417.0188540876.

The spelling of 72521549 in words is "seventy-two million, five hundred twenty-one thousand, five hundred forty-nine".