72218751 has 8 divisors (see below), whose sum is σ = 105045504. Its totient is φ = 43768920.

The previous prime is 72218749. The next prime is 72218767. The reversal of 72218751 is 15781227.

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

It is not a de Polignac number, because 72218751 - 2¹ = 72218749 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (33), and also a Moran number because the ratio is a prime number: 2188447 = 72218751 / (7 + 2 + 2 + 1 + 8 + 7 + 5 + 1).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72218711) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1094191 + ... + 1094256.

It is an arithmetic number, because the mean of its divisors is an integer number (13130688).

Almost surely, 2^72218751 is an apocalyptic number.

72218751 is a deficient number, since it is larger than the sum of its proper divisors (32826753).

72218751 is a wasteful number, since it uses less digits than its factorization.

72218751 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2188461.

The product of its digits is 7840, while the sum is 33.

The square root of 72218751 is about 8498.1616247280. The cubic root of 72218751 is about 416.4376538483.

Adding to 72218751 its reverse (15781227), we get a palindrome (87999978).

The spelling of 72218751 in words is "seventy-two million, two hundred eighteen thousand, seven hundred fifty-one".