72539569 has 2 divisors, whose sum is σ = 72539570. Its totient is φ = 72539568.

The previous prime is 72539567. The next prime is 72539591. The reversal of 72539569 is 96593527.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 72165025 + 374544 = 8495^2 + 612^2 .

It is a cyclic number.

It is not a de Polignac number, because 72539569 - 2¹ = 72539567 is a prime.

It is a super-2 number, since 2×72539569² = 10523978141411522, which contains 22 as substring.

Together with 72539567, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (72539567) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36269784 + 36269785.

It is an arithmetic number, because the mean of its divisors is an integer number (36269785).

Almost surely, 2^72539569 is an apocalyptic number.

It is an amenable number.

72539569 is a deficient number, since it is larger than the sum of its proper divisors (1).

72539569 is an equidigital number, since it uses as much as digits as its factorization.

72539569 is an evil number, because the sum of its binary digits is even.

The product of its digits is 510300, while the sum is 46.

The square root of 72539569 is about 8517.0164376969. The cubic root of 72539569 is about 417.0533912126.

The spelling of 72539569 in words is "seventy-two million, five hundred thirty-nine thousand, five hundred sixty-nine".