12947778551666 has 32 divisors (see below), whose sum is σ = 22696630790400. Its totient is φ = 5424694157376.

The previous prime is 12947778551557. The next prime is 12947778551699. The reversal of 12947778551666 is 66615587774921.

It is a junction number, because it is equal to n+sod(n) for n = 12947778551593 and 12947778551602.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 31292366 + ... + 31703433.

It is an arithmetic number, because the mean of its divisors is an integer number (709269712200).

Almost surely, 2^{12947778551666} is an apocalyptic number.

12947778551666 is a deficient number, since it is larger than the sum of its proper divisors (9748852238734).

12947778551666 is a wasteful number, since it uses less digits than its factorization.

12947778551666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 62996138.

The product of its digits is 1066867200, while the sum is 74.

The spelling of 12947778551666 in words is "twelve trillion, nine hundred forty-seven billion, seven hundred seventy-eight million, five hundred fifty-one thousand, six hundred sixty-six".