1242639 has 6 divisors (see below), whose sum is σ = 1794936. Its totient is φ = 828420.

The previous prime is 1242629. The next prime is 1242641. The reversal of 1242639 is 9362421.

1242639 is a `hidden beast` number, since 1 + 24 + 2 + 639 = 666.

It is not a de Polignac number, because 1242639 - 2⁴ = 1242623 is a prime.

It is a plaindrome in base 14.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1242629) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 69027 + ... + 69044.

It is an arithmetic number, because the mean of its divisors is an integer number (299156).

2^1242639 is an apocalyptic number.

1242639 is a deficient number, since it is larger than the sum of its proper divisors (552297).

1242639 is a wasteful number, since it uses less digits than its factorization.

1242639 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 138077 (or 138074 counting only the distinct ones).

The product of its digits is 2592, while the sum is 27.

The square root of 1242639 is about 1114.7371887580. The cubic root of 1242639 is about 107.5098674916.

It can be divided in two parts, 1242 and 639, that added together give a palindrome (1881).

The spelling of 1242639 in words is "one million, two hundred forty-two thousand, six hundred thirty-nine".