642181172 has 12 divisors (see below), whose sum is σ = 1124830980. Its totient is φ = 320800896.

The previous prime is 642181157. The next prime is 642181201. The reversal of 642181172 is 271181246.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 321269776 + 320911396 = 17924^2 + 17914^2 .

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 67397 + ... + 76332.

It is an arithmetic number, because the mean of its divisors is an integer number (93735915).

Almost surely, 2^642181172 is an apocalyptic number.

It is an amenable number.

642181172 is a deficient number, since it is larger than the sum of its proper divisors (482649808).

642181172 is a wasteful number, since it uses less digits than its factorization.

642181172 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 144850 (or 144848 counting only the distinct ones).

The product of its digits is 5376, while the sum is 32.

The square root of 642181172 is about 25341.2938106956. The cubic root of 642181172 is about 862.7517644078.

The spelling of 642181172 in words is "six hundred forty-two million, one hundred eighty-one thousand, one hundred seventy-two".