72661273 has 4 divisors (see below), whose sum is σ = 73892880. Its totient is φ = 71429668.

The previous prime is 72661249. The next prime is 72661313. The reversal of 72661273 is 37216627.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-72661273 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (72661223) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 615715 + ... + 615832.

It is an arithmetic number, because the mean of its divisors is an integer number (18473220).

Almost surely, 2^72661273 is an apocalyptic number.

It is an amenable number.

72661273 is a deficient number, since it is larger than the sum of its proper divisors (1231607).

72661273 is a wasteful number, since it uses less digits than its factorization.

72661273 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1231606.

The product of its digits is 21168, while the sum is 34.

The square root of 72661273 is about 8524.1581989074. The cubic root of 72661273 is about 417.2864994182.

The spelling of 72661273 in words is "seventy-two million, six hundred sixty-one thousand, two hundred seventy-three".