71388109 has 4 divisors (see below), whose sum is σ = 76879516. Its totient is φ = 65896704.

The previous prime is 71388103. The next prime is 71388173. The reversal of 71388109 is 90188317.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 23474025 + 47914084 = 4845^2 + 6922^2 .

It is a cyclic number.

It is not a de Polignac number, because 71388109 - 2⁵ = 71388077 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 (71388103) 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, 2745684 + ... + 2745709.

It is an arithmetic number, because the mean of its divisors is an integer number (19219879).

Almost surely, 2^71388109 is an apocalyptic number.

It is an amenable number.

71388109 is a deficient number, since it is larger than the sum of its proper divisors (5491407).

71388109 is a wasteful number, since it uses less digits than its factorization.

71388109 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5491406.

The product of its (nonzero) digits is 12096, while the sum is 37.

The square root of 71388109 is about 8449.1484186278. The cubic root of 71388109 is about 414.8349060256.

The spelling of 71388109 in words is "seventy-one million, three hundred eighty-eight thousand, one hundred nine".