11991783049 has 3 divisors (see below), whose sum is σ = 11991892557. Its totient is φ = 11991673542.

The previous prime is 11991783043. The next prime is 11991783053. The reversal of 11991783049 is 94038719911.

The square root of 11991783049 is 109507.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 94038719911 = 22481 ⋅4183031.

It is not a de Polignac number, because 11991783049 - 2³¹ = 9844299401 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 11991782987 and 11991783005.

It is not an unprimeable number, because it can be changed into a prime (11991783043) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 54754 + ... + 164260.

It is an arithmetic number, because the mean of its divisors is an integer number (3997297519).

Almost surely, 2^11991783049 is an apocalyptic number.

11991783049 is the 109507-th square number.

11991783049 is the 54754-th centered octagonal number.

It is an amenable number.

11991783049 is a deficient number, since it is larger than the sum of its proper divisors (109508).

11991783049 is an frugal number, since it uses more digits than its factorization.

11991783049 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 219014 (or 109507 counting only the distinct ones).

The product of its (nonzero) digits is 489888, while the sum is 52.

The spelling of 11991783049 in words is "eleven billion, nine hundred ninety-one million, seven hundred eighty-three thousand, forty-nine".