868428639 has 18 divisors (see below), whose sum is σ = 1358313840. Its totient is φ = 534416688.

The previous prime is 868428623. The next prime is 868428643. The reversal of 868428639 is 936824868.

It is not a de Polignac number, because 868428639 - 2⁴ = 868428623 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (868428439) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 283959 + ... + 287000.

It is an arithmetic number, because the mean of its divisors is an integer number (75461880).

Almost surely, 2^868428639 is an apocalyptic number.

868428639 is a deficient number, since it is larger than the sum of its proper divisors (489885201).

868428639 is a wasteful number, since it uses less digits than its factorization.

868428639 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 570991 (or 570975 counting only the distinct ones).

The product of its digits is 3981312, while the sum is 54.

The square root of 868428639 is about 29469.1133052897. The cubic root of 868428639 is about 954.0651795452.

It can be divided in two parts, 86842 and 8639, that added together give a square (95481 = 309²).

The spelling of 868428639 in words is "eight hundred sixty-eight million, four hundred twenty-eight thousand, six hundred thirty-nine".