121291993 has 4 divisors (see below), whose sum is σ = 121316148. Its totient is φ = 121267840.

The previous prime is 121291979. The next prime is 121292009. The reversal of 121291993 is 399192121.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 399192121 = 1327 ⋅300823.

It can be written as a sum of positive squares in 2 ways, for example, as 12131289 + 109160704 = 3483^2 + 10448^2 .

It is a cyclic number.

It is not a de Polignac number, because 121291993 - 2²¹ = 119194841 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (121291393) 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, 1396 + ... + 15637.

It is an arithmetic number, because the mean of its divisors is an integer number (30329037).

Almost surely, 2^121291993 is an apocalyptic number.

It is an amenable number.

121291993 is a deficient number, since it is larger than the sum of its proper divisors (24155).

121291993 is an equidigital number, since it uses as much as digits as its factorization.

121291993 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24154.

The product of its digits is 8748, while the sum is 37.

The square root of 121291993 is about 11013.2644116084. The cubic root of 121291993 is about 495.0062822724.

The spelling of 121291993 in words is "one hundred twenty-one million, two hundred ninety-one thousand, nine hundred ninety-three".