891121723674 has 320 divisors, whose sum is σ = 2447555927040. Its totient is φ = 214037268480.

The previous prime is 891121723649. The next prime is 891121723717. The reversal of 891121723674 is 476327121198.

It is a Harshad number since it is a multiple of its sum of digits (51).

It is an unprimeable number.

It is a polite number, since it can be written in 159 ways as a sum of consecutive naturals, for example, 98690992 + ... + 98700020.

It is an arithmetic number, because the mean of its divisors is an integer number (7648612272).

Almost surely, 2^891121723674 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 891121723674, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1223777963520).

891121723674 is an abundant number, since it is smaller than the sum of its proper divisors (1556434203366).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

891121723674 is a wasteful number, since it uses less digits than its factorization.

891121723674 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9123 (or 9102 counting only the distinct ones).

The product of its digits is 1016064, while the sum is 51.

The spelling of 891121723674 in words is "eight hundred ninety-one billion, one hundred twenty-one million, seven hundred twenty-three thousand, six hundred seventy-four".