72291247 has 4 divisors (see below), whose sum is σ = 82618576. Its totient is φ = 61963920.

The previous prime is 72291239. The next prime is 72291253. The reversal of 72291247 is 74219227.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 74219227 = 59 ⋅1257953.

It is a cyclic number.

It is not a de Polignac number, because 72291247 - 2³ = 72291239 is a prime.

It is a super-3 number, since 3×72291247³ (a number of 25 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72291347) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5163654 + ... + 5163667.

It is an arithmetic number, because the mean of its divisors is an integer number (20654644).

Almost surely, 2^72291247 is an apocalyptic number.

72291247 is a deficient number, since it is larger than the sum of its proper divisors (10327329).

72291247 is a wasteful number, since it uses less digits than its factorization.

72291247 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10327328.

The product of its digits is 14112, while the sum is 34.

The square root of 72291247 is about 8502.4259479280. The cubic root of 72291247 is about 416.5769527025.

The spelling of 72291247 in words is "seventy-two million, two hundred ninety-one thousand, two hundred forty-seven".