11781661749 has 32 divisors (see below), whose sum is σ = 19257606144. Its totient is φ = 6304562880.

The previous prime is 11781661741. The next prime is 11781661751. The reversal of 11781661749 is 94716618711.

It is not a de Polignac number, because 11781661749 - 2³ = 11781661741 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11781661741) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 587157 + ... + 606890.

It is an arithmetic number, because the mean of its divisors is an integer number (601800192).

Almost surely, 2^11781661749 is an apocalyptic number.

It is an amenable number.

11781661749 is a deficient number, since it is larger than the sum of its proper divisors (7475944395).

11781661749 is a wasteful number, since it uses less digits than its factorization.

11781661749 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1194097.

The product of its digits is 508032, while the sum is 51.

The spelling of 11781661749 in words is "eleven billion, seven hundred eighty-one million, six hundred sixty-one thousand, seven hundred forty-nine".