10991321901 has 24 divisors (see below), whose sum is σ = 18729711104. Its totient is φ = 6078149280.

The previous prime is 10991321893. The next prime is 10991321941. The reversal of 10991321901 is 10912319901.

It is not a de Polignac number, because 10991321901 - 2³ = 10991321893 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 (10991321941) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2812006 + ... + 2815911.

Almost surely, 2^10991321901 is an apocalyptic number.

It is an amenable number.

10991321901 is a deficient number, since it is larger than the sum of its proper divisors (7738389203).

10991321901 is a wasteful number, since it uses less digits than its factorization.

10991321901 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5627961 (or 5627958 counting only the distinct ones).

The product of its (nonzero) digits is 4374, while the sum is 36.

The spelling of 10991321901 in words is "ten billion, nine hundred ninety-one million, three hundred twenty-one thousand, nine hundred one".