642629173 has 2 divisors, whose sum is σ = 642629174. Its totient is φ = 642629172.

The previous prime is 642629161. The next prime is 642629179. The reversal of 642629173 is 371926246.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 539261284 + 103367889 = 23222^2 + 10167^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-642629173 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (642629179) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321314586 + 321314587.

It is an arithmetic number, because the mean of its divisors is an integer number (321314587).

Almost surely, 2^642629173 is an apocalyptic number.

It is an amenable number.

642629173 is a deficient number, since it is larger than the sum of its proper divisors (1).

642629173 is an equidigital number, since it uses as much as digits as its factorization.

642629173 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 108864, while the sum is 40.

The square root of 642629173 is about 25350.1316170153. The cubic root of 642629173 is about 862.9523432187.

The spelling of 642629173 in words is "six hundred forty-two million, six hundred twenty-nine thousand, one hundred seventy-three".