121231993 has 2 divisors, whose sum is σ = 121231994. Its totient is φ = 121231992.

The previous prime is 121231991. The next prime is 121232009. The reversal of 121231993 is 399132121.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 62678889 + 58553104 = 7917^2 + 7652^2 .

It is an emirp because it is prime and its reverse (399132121) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 121231993 - 2¹ = 121231991 is a prime.

It is a super-2 number, since 2×121231993² = 29394392253504098, which contains 22 as substring.

Together with 121231991, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (121231991) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60615996 + 60615997.

It is an arithmetic number, because the mean of its divisors is an integer number (60615997).

Almost surely, 2^121231993 is an apocalyptic number.

It is an amenable number.

121231993 is a deficient number, since it is larger than the sum of its proper divisors (1).

121231993 is an equidigital number, since it uses as much as digits as its factorization.

121231993 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2916, while the sum is 31.

The square root of 121231993 is about 11010.5400866624. The cubic root of 121231993 is about 494.9246465577.

The spelling of 121231993 in words is "one hundred twenty-one million, two hundred thirty-one thousand, nine hundred ninety-three".