639974121783 has 8 divisors (see below), whose sum is σ = 853317376896. Its totient is φ = 426640140600.

The previous prime is 639974121781. The next prime is 639974121803. The reversal of 639974121783 is 387121479936.

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

It is not a de Polignac number, because 639974121783 - 2¹ = 639974121781 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (639974121781) 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, 2155833 + ... + 2434658.

It is an arithmetic number, because the mean of its divisors is an integer number (106664672112).

Almost surely, 2^639974121783 is an apocalyptic number.

639974121783 is a deficient number, since it is larger than the sum of its proper divisors (213343255113).

639974121783 is a wasteful number, since it uses less digits than its factorization.

639974121783 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4636965.

The product of its digits is 13716864, while the sum is 60.

The spelling of 639974121783 in words is "six hundred thirty-nine billion, nine hundred seventy-four million, one hundred twenty-one thousand, seven hundred eighty-three".