15506231188681 has 8 divisors (see below), whose sum is σ = 16457360928264. Its totient is φ = 14559434615040.

The previous prime is 15506231188673. The next prime is 15506231188687. The reversal of 15506231188681 is 18688113260551.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 138576763081 + 15367654425600 = 372259^2 + 3920160^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 15506231188681 - 2³ = 15506231188673 is a prime.

It is a super-2 number, since 2×15506231188681² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (15506231188687) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1083284110 + ... + 1083298423.

It is an arithmetic number, because the mean of its divisors is an integer number (2057170116033).

Almost surely, 2^{15506231188681} is an apocalyptic number.

It is an amenable number.

15506231188681 is a deficient number, since it is larger than the sum of its proper divisors (951129739583).

15506231188681 is a wasteful number, since it uses less digits than its factorization.

15506231188681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2166582971.

The product of its (nonzero) digits is 2764800, while the sum is 55.

The spelling of 15506231188681 in words is "fifteen trillion, five hundred six billion, two hundred thirty-one million, one hundred eighty-eight thousand, six hundred eighty-one".