71644489 has 4 divisors (see below), whose sum is σ = 81879424. Its totient is φ = 61409556.

The previous prime is 71644487. The next prime is 71644519. The reversal of 71644489 is 98444617.

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 an emirpimes, since its reverse is a distinct semiprime: 98444617 = 1181 ⋅83357.

It is a cyclic number.

It is not a de Polignac number, because 71644489 - 2¹ = 71644487 is a prime.

It is a super-2 number, since 2×71644489² = 10265865608142242, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (71644483) 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 3 ways as a sum of consecutive naturals, for example, 5117457 + ... + 5117470.

It is an arithmetic number, because the mean of its divisors is an integer number (20469856).

Almost surely, 2^71644489 is an apocalyptic number.

It is an amenable number.

71644489 is a deficient number, since it is larger than the sum of its proper divisors (10234935).

71644489 is a wasteful number, since it uses less digits than its factorization.

71644489 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10234934.

The product of its digits is 193536, while the sum is 43.

The square root of 71644489 is about 8464.3067642897. The cubic root of 71644489 is about 415.3309191019.

The spelling of 71644489 in words is "seventy-one million, six hundred forty-four thousand, four hundred eighty-nine".