71249989 has 4 divisors (see below), whose sum is σ = 71267040. Its totient is φ = 71232940.

The previous prime is 71249957. The next prime is 71249999. The reversal of 71249989 is 98994217.

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, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 98994217 = 7 ⋅14142031.

It is a cyclic number.

It is not a de Polignac number, because 71249989 - 2⁵ = 71249957 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 (71249999) 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, 2472 + ... + 12190.

It is an arithmetic number, because the mean of its divisors is an integer number (17816760).

Almost surely, 2^71249989 is an apocalyptic number.

It is an amenable number.

71249989 is a deficient number, since it is larger than the sum of its proper divisors (17051).

71249989 is an equidigital number, since it uses as much as digits as its factorization.

71249989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17050.

The product of its digits is 326592, while the sum is 49.

The square root of 71249989 is about 8440.9708564833. The cubic root of 71249989 is about 414.5671957580.

The spelling of 71249989 in words is "seventy-one million, two hundred forty-nine thousand, nine hundred eighty-nine".