9139523661 has 12 divisors (see below), whose sum is σ = 13558332892. Its totient is φ = 5928339456.

The previous prime is 9139523647. The next prime is 9139523671. The reversal of 9139523661 is 1663259319.

9139523661 is a `hidden beast` number, since 91 + 39 + 523 + 6 + 6 + 1 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 5359118436 + 3780405225 = 73206^2 + 61485^2 .

It is not a de Polignac number, because 9139523661 - 2¹⁸ = 9139261517 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9139523671) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 13722676 + ... + 13723341.

Almost surely, 2^9139523661 is an apocalyptic number.

It is an amenable number.

9139523661 is a deficient number, since it is larger than the sum of its proper divisors (4418809231).

9139523661 is a wasteful number, since it uses less digits than its factorization.

9139523661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27446060 (or 27446057 counting only the distinct ones).

The product of its digits is 262440, while the sum is 45.

The square root of 9139523661 is about 95600.8559637412. The cubic root of 9139523661 is about 2090.7776736325. Note that the first 3 decimals are identical.

The spelling of 9139523661 in words is "nine billion, one hundred thirty-nine million, five hundred twenty-three thousand, six hundred sixty-one".