71428609 has 4 divisors (see below), whose sum is σ = 81632704. Its totient is φ = 61224516.

The previous prime is 71428607. The next prime is 71428613. The reversal of 71428609 is 90682417.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 71428609 - 2¹ = 71428607 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (71428603) 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, 5102037 + ... + 5102050.

It is an arithmetic number, because the mean of its divisors is an integer number (20408176).

Almost surely, 2^71428609 is an apocalyptic number.

It is an amenable number.

71428609 is a deficient number, since it is larger than the sum of its proper divisors (10204095).

71428609 is a wasteful number, since it uses less digits than its factorization.

71428609 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10204094.

The product of its (nonzero) digits is 24192, while the sum is 37.

The square root of 71428609 is about 8451.5447700406. The cubic root of 71428609 is about 414.9133394312.

It can be divided in two parts, 7142 and 8609, that added together give a palindrome (15751).

The spelling of 71428609 in words is "seventy-one million, four hundred twenty-eight thousand, six hundred nine".