121251191 has 4 divisors (see below), whose sum is σ = 128383632. Its totient is φ = 114118752.

The previous prime is 121251139. The next prime is 121251209. The reversal of 121251191 is 191152121.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 121251191 - 2⁶ = 121251127 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121253191) 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, 3566195 + ... + 3566228.

It is an arithmetic number, because the mean of its divisors is an integer number (32095908).

Almost surely, 2^121251191 is an apocalyptic number.

121251191 is a deficient number, since it is larger than the sum of its proper divisors (7132441).

121251191 is an equidigital number, since it uses as much as digits as its factorization.

121251191 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7132440.

The product of its digits is 180, while the sum is 23.

The square root of 121251191 is about 11011.4118531640. The cubic root of 121251191 is about 494.9507701950.

The spelling of 121251191 in words is "one hundred twenty-one million, two hundred fifty-one thousand, one hundred ninety-one".