2663978465891 has 2 divisors, whose sum is σ = 2663978465892. Its totient is φ = 2663978465890.

The previous prime is 2663978465887. The next prime is 2663978465899. The reversal of 2663978465891 is 1985648793662.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 2663978465891 - 2² = 2663978465887 is a prime.

It is not a weakly prime, because it can be changed into another prime (2663978465899) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1331989232945 + 1331989232946.

It is an arithmetic number, because the mean of its divisors is an integer number (1331989232946).

Almost surely, 2^{2663978465891} is an apocalyptic number.

2663978465891 is a deficient number, since it is larger than the sum of its proper divisors (1).

2663978465891 is an equidigital number, since it uses as much as digits as its factorization.

2663978465891 is an evil number, because the sum of its binary digits is even.

The product of its digits is 940584960, while the sum is 74.

The spelling of 2663978465891 in words is "two trillion, six hundred sixty-three billion, nine hundred seventy-eight million, four hundred sixty-five thousand, eight hundred ninety-one".