642168479 has 4 divisors (see below), whose sum is σ = 675966840. Its totient is φ = 608370120.

The previous prime is 642168469. The next prime is 642168509. The reversal of 642168479 is 974861246.

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

It is not a de Polignac number, because 642168479 - 2⁸ = 642168223 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 (642168409) 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 in 3 ways as a sum of consecutive naturals, for example, 16899152 + ... + 16899189.

It is an arithmetic number, because the mean of its divisors is an integer number (168991710).

Almost surely, 2^642168479 is an apocalyptic number.

642168479 is a deficient number, since it is larger than the sum of its proper divisors (33798361).

642168479 is a wasteful number, since it uses less digits than its factorization.

642168479 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33798360.

The product of its digits is 580608, while the sum is 47.

The square root of 642168479 is about 25341.0433684172. The cubic root of 642168479 is about 862.7460801447.

The spelling of 642168479 in words is "six hundred forty-two million, one hundred sixty-eight thousand, four hundred seventy-nine".