642638015806 has 8 divisors (see below), whose sum is σ = 964536678144. Its totient is φ = 321125789760.

The previous prime is 642638015801. The next prime is 642638015857. The reversal of 642638015806 is 608510836246.

It is a happy number.

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

It is a super-3 number, since 3×642638015806³ (a number of 36 digits) contains 333 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 642638015806.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (642638015801) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 96604915 + ... + 96611566.

It is an arithmetic number, because the mean of its divisors is an integer number (120567084768).

Almost surely, 2^642638015806 is an apocalyptic number.

642638015806 is a deficient number, since it is larger than the sum of its proper divisors (321898662338).

642638015806 is a wasteful number, since it uses less digits than its factorization.

642638015806 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 193218146.

The product of its (nonzero) digits is 1658880, while the sum is 49.

The spelling of 642638015806 in words is "six hundred forty-two billion, six hundred thirty-eight million, fifteen thousand, eight hundred six".