642445687 has 8 divisors (see below), whose sum is σ = 708739920. Its totient is φ = 578562240.

The previous prime is 642445681. The next prime is 642445693. The reversal of 642445687 is 786544246.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (642445681) and next prime (642445693).

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 642445687 - 2¹¹ = 642443639 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 (642445681) 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 7 ways as a sum of consecutive naturals, for example, 602137 + ... + 603202.

It is an arithmetic number, because the mean of its divisors is an integer number (88592490).

Almost surely, 2^642445687 is an apocalyptic number.

642445687 is a deficient number, since it is larger than the sum of its proper divisors (66294233).

642445687 is a wasteful number, since it uses less digits than its factorization.

642445687 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1205393.

The product of its digits is 1290240, while the sum is 46.

The square root of 642445687 is about 25346.5123241838. The cubic root of 642445687 is about 862.8702042224.

The spelling of 642445687 in words is "six hundred forty-two million, four hundred forty-five thousand, six hundred eighty-seven".