12191761 has 4 divisors (see below), whose sum is σ = 12204724. Its totient is φ = 12178800.

The previous prime is 12191741. The next prime is 12191779. The reversal of 12191761 is 16719121.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 16719121 = 1201 ⋅13921.

It can be written as a sum of positive squares in 2 ways, for example, as 5089536 + 7102225 = 2256^2 + 2665^2 .

It is a cyclic number.

It is not a de Polignac number, because 12191761 - 2¹³ = 12183569 is a prime.

It is a super-2 number, since 2×12191761² = 297278072562242, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12191741) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4950 + ... + 6991.

It is an arithmetic number, because the mean of its divisors is an integer number (3051181).

Almost surely, 2^12191761 is an apocalyptic number.

It is an amenable number.

12191761 is a deficient number, since it is larger than the sum of its proper divisors (12963).

12191761 is a wasteful number, since it uses less digits than its factorization.

12191761 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12962.

The product of its digits is 756, while the sum is 28.

The square root of 12191761 is about 3491.6702307062. The cubic root of 12191761 is about 230.1559182229.

The spelling of 12191761 in words is "twelve million, one hundred ninety-one thousand, seven hundred sixty-one".