72661636 has 12 divisors (see below), whose sum is σ = 130594828. Its totient is φ = 35348832.

The previous prime is 72661619. The next prime is 72661637. The reversal of 72661636 is 63616627.

It can be written as a sum of positive squares in 2 ways, for example, as 33524100 + 39137536 = 5790^2 + 6256^2 .

It is a Harshad number since it is a multiple of its sum of digits (37).

It is a junction number, because it is equal to n+sod(n) for n = 72661595 and 72661604.

It is not an unprimeable number, because it can be changed into a prime (72661637) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 245331 + ... + 245626.

Almost surely, 2^72661636 is an apocalyptic number.

It is an amenable number.

72661636 is a deficient number, since it is larger than the sum of its proper divisors (57933192).

72661636 is a wasteful number, since it uses less digits than its factorization.

72661636 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 490998 (or 490996 counting only the distinct ones).

The product of its digits is 54432, while the sum is 37.

The square root of 72661636 is about 8524.1794913059. The cubic root of 72661636 is about 417.2871943081.

The spelling of 72661636 in words is "seventy-two million, six hundred sixty-one thousand, six hundred thirty-six".