102639 has 4 divisors (see below), whose sum is σ = 136856. Its totient is φ = 68424.

The previous prime is 102611. The next prime is 102643. The reversal of 102639 is 936201.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 102639 - 2⁵ = 102607 is a prime.

It is a D-number.

It is a Duffinian number.

102639 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (102679) 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, 17104 + ... + 17109.

It is an arithmetic number, because the mean of its divisors is an integer number (34214).

2¹⁰²⁶³⁹ is an apocalyptic number.

102639 is a deficient number, since it is larger than the sum of its proper divisors (34217).

102639 is an equidigital number, since it uses as much as digits as its factorization.

102639 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34216.

The product of its (nonzero) digits is 324, while the sum is 21.

The square root of 102639 is about 320.3732198546. The cubic root of 102639 is about 46.8206534598.

It can be divided in two parts, 102 and 639, that added together give a triangular number (741 = T₃₈).

The spelling of 102639 in words is "one hundred two thousand, six hundred thirty-nine".