72060721 has 4 divisors (see below), whose sum is σ = 72544500. Its totient is φ = 71576944.

The previous prime is 72060649. The next prime is 72060727. The reversal of 72060721 is 12706027.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 12215025 + 59845696 = 3495^2 + 7736^2 .

It is a cyclic number.

It is not a de Polignac number, because 72060721 - 2²⁵ = 38506289 is a prime.

It is a super-2 number, since 2×72060721² = 10385495022079682, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (72060727) 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 in 3 ways as a sum of consecutive naturals, for example, 241666 + ... + 241963.

It is an arithmetic number, because the mean of its divisors is an integer number (18136125).

Almost surely, 2^72060721 is an apocalyptic number.

It is an amenable number.

72060721 is a deficient number, since it is larger than the sum of its proper divisors (483779).

72060721 is a wasteful number, since it uses less digits than its factorization.

72060721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 483778.

The product of its (nonzero) digits is 1176, while the sum is 25.

The square root of 72060721 is about 8488.8586394167. The cubic root of 72060721 is about 416.1336806106.

Adding to 72060721 its reverse (12706027), we get a palindrome (84766748).

The spelling of 72060721 in words is "seventy-two million, sixty thousand, seven hundred twenty-one".