2051866978666 has 8 divisors (see below), whose sum is σ = 3086186846400. Its totient is φ = 1023138029868.

The previous prime is 2051866978657. The next prime is 2051866978697. The reversal of 2051866978666 is 6668796681502.

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

It is a junction number, because it is equal to n+sod(n) for n = 2051866978595 and 2051866978604.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1397728816 + ... + 1397730283.

It is an arithmetic number, because the mean of its divisors is an integer number (385773355800).

Almost surely, 2^{2051866978666} is an apocalyptic number.

2051866978666 is a deficient number, since it is larger than the sum of its proper divisors (1034319867734).

2051866978666 is a wasteful number, since it uses less digits than its factorization.

2051866978666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2795459468.

The product of its (nonzero) digits is 313528320, while the sum is 70.

The spelling of 2051866978666 in words is "two trillion, fifty-one billion, eight hundred sixty-six million, nine hundred seventy-eight thousand, six hundred sixty-six".