15781891876 has 27 divisors (see below), whose sum is σ = 28881891003. Its totient is φ = 7545097560.

The previous prime is 15781891849. The next prime is 15781891889. The reversal of 15781891876 is 67819818751.

The square root of 15781891876 is 125626.

It is a perfect power (a square), and thus also a powerful number.

15781891876 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×15781891876² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 5777431 + ... + 5780161.

Almost surely, 2^15781891876 is an apocalyptic number.

15781891876 is the 125626-th square number.

It is an amenable number.

15781891876 is a deficient number, since it is larger than the sum of its proper divisors (13099999127).

15781891876 is an frugal number, since it uses more digits than its factorization.

15781891876 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5512 (or 2756 counting only the distinct ones).

The product of its digits is 6773760, while the sum is 61.

The spelling of 15781891876 in words is "fifteen billion, seven hundred eighty-one million, eight hundred ninety-one thousand, eight hundred seventy-six".