15978487869 has 32 divisors (see below), whose sum is σ = 24219072000. Its totient is φ = 10406886912.

The previous prime is 15978487843. The next prime is 15978487873. The reversal of 15978487869 is 96878487951.

15978487869 is a `hidden beast` number, since 15 + 9 + 78 + 487 + 8 + 69 = 666.

It is not a de Polignac number, because 15978487869 - 2¹⁶ = 15978422333 is a prime.

It is a super-3 number, since 3×15978487869³ (a number of 32 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a junction number, because it is equal to n+sod(n) for n = 15978487797 and 15978487806.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (15978487829) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 710997 + ... + 733125.

It is an arithmetic number, because the mean of its divisors is an integer number (756846000).

Almost surely, 2^15978487869 is an apocalyptic number.

It is an amenable number.

15978487869 is a deficient number, since it is larger than the sum of its proper divisors (8240584131).

15978487869 is a wasteful number, since it uses less digits than its factorization.

15978487869 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22754 (or 22748 counting only the distinct ones).

The product of its digits is 243855360, while the sum is 72.

The spelling of 15978487869 in words is "fifteen billion, nine hundred seventy-eight million, four hundred eighty-seven thousand, eight hundred sixty-nine".