10991872 has 18 divisors (see below), whose sum is σ = 21941318. Its totient is φ = 5495808.

The previous prime is 10991867. The next prime is 10991873. The reversal of 10991872 is 27819901.

It can be written as a sum of positive squares in only one way, i.e., 5683456 + 5308416 = 2384^2 + 2304^2 .

It is not an unprimeable number, because it can be changed into a prime (10991873) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21213 + ... + 21724.

Almost surely, 2^10991872 is an apocalyptic number.

It is an amenable number.

10991872 is a deficient number, since it is larger than the sum of its proper divisors (10949446).

10991872 is an frugal number, since it uses more digits than its factorization.

10991872 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42953 (or 42939 counting only the distinct ones).

The product of its (nonzero) digits is 9072, while the sum is 37.

The square root of 10991872 is about 3315.3992218133. The cubic root of 10991872 is about 222.3432182560.

The spelling of 10991872 in words is "ten million, nine hundred ninety-one thousand, eight hundred seventy-two".