12947778551665 has 16 divisors (see below), whose sum is σ = 16355997112320. Its totient is φ = 9812508168960.

The previous prime is 12947778551557. The next prime is 12947778551699. The reversal of 12947778551665 is 56615587774921.

It is not a de Polignac number, because 12947778551665 - 2²³ = 12947770163057 is a prime.

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, 2061576 + ... + 5490505.

It is an arithmetic number, because the mean of its divisors is an integer number (1022249819520).

Almost surely, 2^{12947778551665} is an apocalyptic number.

It is an amenable number.

12947778551665 is a deficient number, since it is larger than the sum of its proper divisors (3408218560655).

12947778551665 is a wasteful number, since it uses less digits than its factorization.

12947778551665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7570152.

The product of its digits is 889056000, while the sum is 73.

The spelling of 12947778551665 in words is "twelve trillion, nine hundred forty-seven billion, seven hundred seventy-eight million, five hundred fifty-one thousand, six hundred sixty-five".