74639 has 4 divisors (see below), whose sum is σ = 75480. Its totient is φ = 73800.

The previous prime is 74623. The next prime is 74653. The reversal of 74639 is 93647.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 93647 = 37 ⋅2531.

It is a cyclic number.

It is not a de Polignac number, because 74639 - 2⁴ = 74623 is a prime.

It is a Duffinian number.

It is a plaindrome in base 16.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (74609) 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, 269 + ... + 470.

It is an arithmetic number, because the mean of its divisors is an integer number (18870).

2⁷⁴⁶³⁹ is an apocalyptic number.

74639 is a deficient number, since it is larger than the sum of its proper divisors (841).

74639 is a wasteful number, since it uses less digits than its factorization.

74639 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 840.

The product of its digits is 4536, while the sum is 29.

The square root of 74639 is about 273.2013909189. The cubic root of 74639 is about 42.1038623712.

The spelling of 74639 in words is "seventy-four thousand, six hundred thirty-nine".