72212217 has 32 divisors (see below), whose sum is σ = 126366720. Its totient is φ = 35536320.

The previous prime is 72212213. The next prime is 72212279. The reversal of 72212217 is 71221227.

It is not a de Polignac number, because 72212217 - 2² = 72212213 is a prime.

It is not an unprimeable number, because it can be changed into a prime (72212213) 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 31 ways as a sum of consecutive naturals, for example, 3838 + ... + 12615.

It is an arithmetic number, because the mean of its divisors is an integer number (3948960).

Almost surely, 2^72212217 is an apocalyptic number.

72212217 is a gapful number since it is divisible by the number (77) formed by its first and last digit.

It is an amenable number.

72212217 is a deficient number, since it is larger than the sum of its proper divisors (54154503).

72212217 is a wasteful number, since it uses less digits than its factorization.

72212217 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16493.

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

The square root of 72212217 is about 8497.7771799454. Note that the first 3 decimals coincide. The cubic root of 72212217 is about 416.4250943876.

The spelling of 72212217 in words is "seventy-two million, two hundred twelve thousand, two hundred seventeen".