642015678617 has 4 divisors (see below), whose sum is σ = 644513794356. Its totient is φ = 639517562880.

The previous prime is 642015678607. The next prime is 642015678641. The reversal of 642015678617 is 716876510246.

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

It can be written as a sum of positive squares in 2 ways, for example, as 495396376336 + 146619302281 = 703844^2 + 382909^2 .

It is a cyclic number.

It is not a de Polignac number, because 642015678617 - 2⁶ = 642015678553 is a prime.

It is a super-3 number, since 3×642015678617³ (a number of 36 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (642015678607) 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, 1249057484 + ... + 1249057997.

It is an arithmetic number, because the mean of its divisors is an integer number (161128448589).

Almost surely, 2^642015678617 is an apocalyptic number.

It is an amenable number.

642015678617 is a deficient number, since it is larger than the sum of its proper divisors (2498115739).

642015678617 is a wasteful number, since it uses less digits than its factorization.

642015678617 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2498115738.

The product of its (nonzero) digits is 3386880, while the sum is 53.

The spelling of 642015678617 in words is "six hundred forty-two billion, fifteen million, six hundred seventy-eight thousand, six hundred seventeen".