642126349 has 4 divisors (see below), whose sum is σ = 645838236. Its totient is φ = 638414464.

The previous prime is 642126341. The next prime is 642126371. The reversal of 642126349 is 943621246.

It is a happy number.

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

It can be written as a sum of positive squares in 2 ways, for example, as 525097225 + 117029124 = 22915^2 + 10818^2 .

It is a cyclic number.

It is not a de Polignac number, because 642126349 - 2³ = 642126341 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 (642126341) 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, 1855684 + ... + 1856029.

It is an arithmetic number, because the mean of its divisors is an integer number (161459559).

Almost surely, 2^642126349 is an apocalyptic number.

It is an amenable number.

642126349 is a deficient number, since it is larger than the sum of its proper divisors (3711887).

642126349 is a wasteful number, since it uses less digits than its factorization.

642126349 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3711886.

The product of its digits is 62208, while the sum is 37.

The square root of 642126349 is about 25340.2120946136. The cubic root of 642126349 is about 862.7272126728.

The spelling of 642126349 in words is "six hundred forty-two million, one hundred twenty-six thousand, three hundred forty-nine".