1298639 has 4 divisors (see below), whose sum is σ = 1300920. Its totient is φ = 1296360.

The previous prime is 1298617. The next prime is 1298641. The reversal of 1298639 is 9368921.

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: 9368921 = 17 ⋅551113.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1298639 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1298699) 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, 524 + ... + 1694.

It is an arithmetic number, because the mean of its divisors is an integer number (325230).

2^1298639 is an apocalyptic number.

1298639 is a deficient number, since it is larger than the sum of its proper divisors (2281).

1298639 is a wasteful number, since it uses less digits than its factorization.

1298639 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2280.

The product of its digits is 23328, while the sum is 38.

The square root of 1298639 is about 1139.5784308243. The cubic root of 1298639 is about 109.1011881939.

The spelling of 1298639 in words is "one million, two hundred ninety-eight thousand, six hundred thirty-nine".