72140721 has 8 divisors (see below), whose sum is σ = 96226944. Its totient is φ = 48074160.

The previous prime is 72140693. The next prime is 72140729. The reversal of 72140721 is 12704127.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 72140721 - 2²¹ = 70043569 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 72140691 and 72140700.

It is not an unprimeable number, because it can be changed into a prime (72140729) 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 7 ways as a sum of consecutive naturals, for example, 11176 + ... + 16406.

It is an arithmetic number, because the mean of its divisors is an integer number (12028368).

Almost surely, 2^72140721 is an apocalyptic number.

It is an amenable number.

72140721 is a deficient number, since it is larger than the sum of its proper divisors (24086223).

72140721 is a wasteful number, since it uses less digits than its factorization.

72140721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9831.

The product of its (nonzero) digits is 784, while the sum is 24.

The square root of 72140721 is about 8493.5693910158. The cubic root of 72140721 is about 416.2876173743.

Adding to 72140721 its reverse (12704127), we get a palindrome (84844848).

The spelling of 72140721 in words is "seventy-two million, one hundred forty thousand, seven hundred twenty-one".