12891959897 has 4 divisors (see below), whose sum is σ = 12892273680. Its totient is φ = 12891646116.

The previous prime is 12891959881. The next prime is 12891959923. The reversal of 12891959897 is 79895919821.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 12891959897 - 2⁴ = 12891959881 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12891959807) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 83963 + ... + 181200.

It is an arithmetic number, because the mean of its divisors is an integer number (3223068420).

Almost surely, 2^12891959897 is an apocalyptic number.

It is an amenable number.

12891959897 is a deficient number, since it is larger than the sum of its proper divisors (313783).

12891959897 is an equidigital number, since it uses as much as digits as its factorization.

12891959897 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 313782.

The product of its digits is 29393280, while the sum is 68.

The spelling of 12891959897 in words is "twelve billion, eight hundred ninety-one million, nine hundred fifty-nine thousand, eight hundred ninety-seven".