71372509 has 24 divisors (see below), whose sum is σ = 82577880. Its totient is φ = 61246080.

The previous prime is 71372467. The next prime is 71372527. The reversal of 71372509 is 90527317.

It can be written as a sum of positive squares in 4 ways, for example, as 18301284 + 53071225 = 4278^2 + 7285^2 .

It is a de Polignac number, because none of the positive numbers 2^k-71372509 is a prime.

It is a house number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (71372009) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 362199 + ... + 362395.

It is an arithmetic number, because the mean of its divisors is an integer number (3440745).

Almost surely, 2^71372509 is an apocalyptic number.

It is an amenable number.

71372509 is a deficient number, since it is larger than the sum of its proper divisors (11205371).

71372509 is a wasteful number, since it uses less digits than its factorization.

71372509 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 301 (or 270 counting only the distinct ones).

The product of its (nonzero) digits is 13230, while the sum is 34.

The square root of 71372509 is about 8448.2251982295. The cubic root of 71372509 is about 414.8046867259.

The spelling of 71372509 in words is "seventy-one million, three hundred seventy-two thousand, five hundred nine".