921279127891 has 4 divisors (see below), whose sum is σ = 921283268752. Its totient is φ = 921274987032.

The previous prime is 921279127889. The next prime is 921279127897. The reversal of 921279127891 is 198721972129.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 921279127891 - 2¹ = 921279127889 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (921279127897) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1716540 + ... + 2188393.

It is an arithmetic number, because the mean of its divisors is an integer number (230320817188).

Almost surely, 2^921279127891 is an apocalyptic number.

921279127891 is a deficient number, since it is larger than the sum of its proper divisors (4140861).

921279127891 is a wasteful number, since it uses less digits than its factorization.

921279127891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4140860.

The product of its digits is 2286144, while the sum is 58.

The spelling of 921279127891 in words is "nine hundred twenty-one billion, two hundred seventy-nine million, one hundred twenty-seven thousand, eight hundred ninety-one".