3935121638 has 8 divisors (see below), whose sum is σ = 6745922832. Its totient is φ = 1686480696.

The previous prime is 3935121637. The next prime is 3935121647. The reversal of 3935121638 is 8361215393.

It is a happy number.

3935121638 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is a junction number, because it is equal to n+sod(n) for n = 3935121595 and 3935121604.

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 polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 140540045 + ... + 140540072.

It is an arithmetic number, because the mean of its divisors is an integer number (843240354).

Almost surely, 2^3935121638 is an apocalyptic number.

3935121638 is a deficient number, since it is larger than the sum of its proper divisors (2810801194).

3935121638 is a wasteful number, since it uses less digits than its factorization.

3935121638 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 281080126.

The product of its digits is 116640, while the sum is 41.

The square root of 3935121638 is about 62730.5478853804. The cubic root of 3935121638 is about 1578.7718969728.

The spelling of 3935121638 in words is "three billion, nine hundred thirty-five million, one hundred twenty-one thousand, six hundred thirty-eight".