9639121538 has 8 divisors (see below), whose sum is σ = 14459768460. Its totient is φ = 4819198720.

The previous prime is 9639121537. The next prime is 9639121579. The reversal of 9639121538 is 8351219369.

It can be written as a sum of positive squares in 2 ways, for example, as 9614390809 + 24730729 = 98053^2 + 4973^2 .

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 = 9639121492 and 9639121501.

It is not an unprimeable number, because it can be changed into a prime (9639121537) 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, 146423 + ... + 201786.

Almost surely, 2^9639121538 is an apocalyptic number.

9639121538 is a deficient number, since it is larger than the sum of its proper divisors (4820646922).

9639121538 is a wasteful number, since it uses less digits than its factorization.

9639121538 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 362052.

The product of its digits is 349920, while the sum is 47.

The square root of 9639121538 is about 98179.0279947810. The cubic root of 9639121538 is about 2128.2002281645.

The spelling of 9639121538 in words is "nine billion, six hundred thirty-nine million, one hundred twenty-one thousand, five hundred thirty-eight".