1642139 has 4 divisors (see below), whose sum is σ = 1660680. Its totient is φ = 1623600.

The previous prime is 1642117. The next prime is 1642141. The reversal of 1642139 is 9312461.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1642139 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1642339) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9137 + ... + 9314.

It is an arithmetic number, because the mean of its divisors is an integer number (415170).

2^1642139 is an apocalyptic number.

1642139 is a deficient number, since it is larger than the sum of its proper divisors (18541).

1642139 is an equidigital number, since it uses as much as digits as its factorization.

1642139 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18540.

The product of its digits is 1296, while the sum is 26.

The square root of 1642139 is about 1281.4597145443. The cubic root of 1642139 is about 117.9786181693.

The spelling of 1642139 in words is "one million, six hundred forty-two thousand, one hundred thirty-nine".