12125781 has 20 divisors (see below), whose sum is σ = 19069600. Its totient is φ = 7657416.

The previous prime is 12125767. The next prime is 12125803. The reversal of 12125781 is 18752121.

It is not a de Polignac number, because 12125781 - 2¹⁵ = 12093013 is a prime.

It is a super-2 number, since 2×12125781² = 294069129719922, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12125731) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 2401 + ... + 5478.

It is an arithmetic number, because the mean of its divisors is an integer number (953480).

Almost surely, 2^12125781 is an apocalyptic number.

It is an amenable number.

12125781 is a deficient number, since it is larger than the sum of its proper divisors (6943819).

12125781 is an equidigital number, since it uses as much as digits as its factorization.

12125781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7910 (or 7901 counting only the distinct ones).

The product of its digits is 1120, while the sum is 27.

The square root of 12125781 is about 3482.2092125546. The cubic root of 12125781 is about 229.7399770974.

The spelling of 12125781 in words is "twelve million, one hundred twenty-five thousand, seven hundred eighty-one".