3935121639 has 4 divisors (see below), whose sum is σ = 5246828856. Its totient is φ = 2623414424.

The previous prime is 3935121637. The next prime is 3935121647. The reversal of 3935121639 is 9361215393.

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

It is a cyclic number.

It is not a de Polignac number, because 3935121639 - 2¹ = 3935121637 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 3935121639.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3935121637) 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, 655853604 + ... + 655853609.

It is an arithmetic number, because the mean of its divisors is an integer number (1311707214).

Almost surely, 2^3935121639 is an apocalyptic number.

3935121639 is a deficient number, since it is larger than the sum of its proper divisors (1311707217).

3935121639 is a wasteful number, since it uses less digits than its factorization.

3935121639 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1311707216.

The product of its digits is 131220, while the sum is 42.

The square root of 3935121639 is about 62730.5478933510. The cubic root of 3935121639 is about 1578.7718971065.

The spelling of 3935121639 in words is "three billion, nine hundred thirty-five million, one hundred twenty-one thousand, six hundred thirty-nine".