76639 has 4 divisors (see below), whose sum is σ = 77256. Its totient is φ = 76024.

The previous prime is 76631. The next prime is 76649. The reversal of 76639 is 93667.

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: 93667 = 7 ⋅13381.

It is a cyclic number.

It is not a de Polignac number, because 76639 - 2³ = 76631 is a prime.

It is a Duffinian number.

76639 is a lucky number.

It is a self number, because there is not a number n which added to its sum of digits gives 76639.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (76631) 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, 49 + ... + 394.

It is an arithmetic number, because the mean of its divisors is an integer number (19314).

2⁷⁶⁶³⁹ is an apocalyptic number.

76639 is a deficient number, since it is larger than the sum of its proper divisors (617).

76639 is a wasteful number, since it uses less digits than its factorization.

76639 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 616.

The product of its digits is 6804, while the sum is 31.

The square root of 76639 is about 276.8374974602. The cubic root of 76639 is about 42.4766192043.

The spelling of 76639 in words is "seventy-six thousand, six hundred thirty-nine".