72353721 has 32 divisors (see below), whose sum is σ = 109817856. Its totient is φ = 41976000.

The previous prime is 72353693. The next prime is 72353773. The reversal of 72353721 is 12735327.

It is not a de Polignac number, because 72353721 - 2⁶ = 72353657 is a prime.

It is a Smith number, since the sum of its digits (30) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is not an unprimeable number, because it can be changed into a prime (72355721) 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 31 ways as a sum of consecutive naturals, for example, 109131 + ... + 109791.

It is an arithmetic number, because the mean of its divisors is an integer number (3431808).

Almost surely, 2^72353721 is an apocalyptic number.

It is an amenable number.

72353721 is a deficient number, since it is larger than the sum of its proper divisors (37464135).

72353721 is a wasteful number, since it uses less digits than its factorization.

72353721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 813.

The product of its digits is 8820, while the sum is 30.

The square root of 72353721 is about 8506.0990471543. The cubic root of 72353721 is about 416.6969199011.

The spelling of 72353721 in words is "seventy-two million, three hundred fifty-three thousand, seven hundred twenty-one".