55639 has 2 divisors, whose sum is σ = 55640. Its totient is φ = 55638.

The previous prime is 55633. The next prime is 55661. The reversal of 55639 is 93655.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 55639 - 2³ = 55631 is a prime.

55639 is a lucky number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (55631) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27819 + 27820.

It is an arithmetic number, because the mean of its divisors is an integer number (27820).

2⁵⁵⁶³⁹ is an apocalyptic number.

55639 is a deficient number, since it is larger than the sum of its proper divisors (1).

55639 is an equidigital number, since it uses as much as digits as its factorization.

55639 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4050, while the sum is 28.

The square root of 55639 is about 235.8792063748. The cubic root of 55639 is about 38.1762358705.

Subtracting from 55639 its sum of digits (28), we obtain a triangular number (55611 = T₃₃₃).

It can be divided in two parts, 556 and 39, that added together give a palindrome (595).

The spelling of 55639 in words is "fifty-five thousand, six hundred thirty-nine".