71221247 has 4 divisors (see below), whose sum is σ = 71486280. Its totient is φ = 70956216.

The previous prime is 71221217. The next prime is 71221259. The reversal of 71221247 is 74212217.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 74212217 = 3517 ⋅21101.

It is a cyclic number.

It is not a de Polignac number, because 71221247 - 2¹⁰ = 71220223 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (71221207) 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, 132113 + ... + 132650.

It is an arithmetic number, because the mean of its divisors is an integer number (17871570).

Almost surely, 2^71221247 is an apocalyptic number.

71221247 is a deficient number, since it is larger than the sum of its proper divisors (265033).

71221247 is a wasteful number, since it uses less digits than its factorization.

71221247 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 265032.

The product of its digits is 1568, while the sum is 26.

The square root of 71221247 is about 8439.2681554741. The cubic root of 71221247 is about 414.5114432679.

The spelling of 71221247 in words is "seventy-one million, two hundred twenty-one thousand, two hundred forty-seven".