72172646 has 32 divisors (see below), whose sum is σ = 133670208. Its totient is φ = 28460160.

The previous prime is 72172631. The next prime is 72172649. The reversal of 72172646 is 64627127.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72172649) 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 15 ways as a sum of consecutive naturals, for example, 98096 + ... + 98828.

It is an arithmetic number, because the mean of its divisors is an integer number (4177194).

Almost surely, 2^72172646 is an apocalyptic number.

72172646 is a deficient number, since it is larger than the sum of its proper divisors (61497562).

72172646 is a wasteful number, since it uses less digits than its factorization.

72172646 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1296.

The product of its digits is 28224, while the sum is 35.

The square root of 72172646 is about 8495.4485461334. The cubic root of 72172646 is about 416.3490159946.

The spelling of 72172646 in words is "seventy-two million, one hundred seventy-two thousand, six hundred forty-six".