72215217 has 12 divisors (see below), whose sum is σ = 104916084. Its totient is φ = 47864160.

The previous prime is 72215183. The next prime is 72215237. The reversal of 72215217 is 71251227.

It can be written as a sum of positive squares in 2 ways, for example, as 57744801 + 14470416 = 7599^2 + 3804^2 .

It is not a de Polignac number, because 72215217 - 2⁶ = 72215153 is a prime.

It is not an unprimeable number, because it can be changed into a prime (72215237) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 21634 + ... + 24747.

It is an arithmetic number, because the mean of its divisors is an integer number (8743007).

Almost surely, 2^72215217 is an apocalyptic number.

It is an amenable number.

72215217 is a deficient number, since it is larger than the sum of its proper divisors (32700867).

72215217 is a wasteful number, since it uses less digits than its factorization.

72215217 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 46560 (or 46557 counting only the distinct ones).

The product of its digits is 1960, while the sum is 27.

The square root of 72215217 is about 8497.9536948609. The cubic root of 72215217 is about 416.4308609926.

The spelling of 72215217 in words is "seventy-two million, two hundred fifteen thousand, two hundred seventeen".