12195781 has 8 divisors (see below), whose sum is σ = 13163360. Its totient is φ = 11232432.

The previous prime is 12195779. The next prime is 12195787. The reversal of 12195781 is 18759121.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 12195781 - 2¹ = 12195779 is a prime.

It is a super-2 number, since 2×12195781² = 297474148399922, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12195787) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7630 + ... + 9088.

It is an arithmetic number, because the mean of its divisors is an integer number (1645420).

Almost surely, 2^12195781 is an apocalyptic number.

It is an amenable number.

12195781 is a deficient number, since it is larger than the sum of its proper divisors (967579).

12195781 is a wasteful number, since it uses less digits than its factorization.

12195781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2115.

The product of its digits is 5040, while the sum is 34.

The square root of 12195781 is about 3492.2458389982. The cubic root of 12195781 is about 230.1812119470.

The spelling of 12195781 in words is "twelve million, one hundred ninety-five thousand, seven hundred eighty-one".