991124343221 has 8 divisors (see below), whose sum is σ = 993725091840. Its totient is φ = 988523866512.

The previous prime is 991124343199. The next prime is 991124343241. The reversal of 991124343221 is 122343421199.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-991124343221 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (991124343241) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8712716 + ... + 8825738.

It is an arithmetic number, because the mean of its divisors is an integer number (124215636480).

Almost surely, 2^991124343221 is an apocalyptic number.

It is an amenable number.

991124343221 is a deficient number, since it is larger than the sum of its proper divisors (2600748619).

991124343221 is a wasteful number, since it uses less digits than its factorization.

991124343221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 135955.

The product of its digits is 93312, while the sum is 41.

The spelling of 991124343221 in words is "nine hundred ninety-one billion, one hundred twenty-four million, three hundred forty-three thousand, two hundred twenty-one".