12121993 has 8 divisors (see below), whose sum is σ = 13190408. Its totient is φ = 11073024.

The previous prime is 12121987. The next prime is 12122009. The reversal of 12121993 is 39912121.

It can be written as a sum of positive squares in 4 ways, for example, as 3139984 + 8982009 = 1772^2 + 2997^2 .

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 12121993 - 2⁹ = 12121481 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12121973) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3546 + ... + 6067.

It is an arithmetic number, because the mean of its divisors is an integer number (1648801).

Almost surely, 2^12121993 is an apocalyptic number.

12121993 is a gapful number since it is divisible by the number (13) formed by its first and last digit.

It is an amenable number.

12121993 is a deficient number, since it is larger than the sum of its proper divisors (1068415).

12121993 is an equidigital number, since it uses as much as digits as its factorization.

12121993 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9723.

The product of its digits is 972, while the sum is 28.

The square root of 12121993 is about 3481.6652624858. The cubic root of 12121993 is about 229.7160516098.

The spelling of 12121993 in words is "twelve million, one hundred twenty-one thousand, nine hundred ninety-three".