71428209 has 8 divisors (see below), whose sum is σ = 95292480. Its totient is φ = 47591376.

The previous prime is 71428207. The next prime is 71428213. The reversal of 71428209 is 90282417.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 71428209 - 2¹ = 71428207 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 71428209.

It is not an unprimeable number, because it can be changed into a prime (71428207) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 279 + ... + 11955.

It is an arithmetic number, because the mean of its divisors is an integer number (11911560).

Almost surely, 2^71428209 is an apocalyptic number.

It is an amenable number.

71428209 is a deficient number, since it is larger than the sum of its proper divisors (23864271).

71428209 is a wasteful number, since it uses less digits than its factorization.

71428209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13719.

The product of its (nonzero) digits is 8064, while the sum is 33.

The square root of 71428209 is about 8451.5211056945. The cubic root of 71428209 is about 414.9125649253.

It can be divided in two parts, 7142 and 8209, that added together give a palindrome (15351).

The spelling of 71428209 in words is "seventy-one million, four hundred twenty-eight thousand, two hundred nine".