121291691 has 4 divisors (see below), whose sum is σ = 124112472. Its totient is φ = 118470912.

The previous prime is 121291663. The next prime is 121291697. The reversal of 121291691 is 196192121.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 196192121 = 17 ⋅11540713.

It is a cyclic number.

It is not a de Polignac number, because 121291691 - 2¹⁰ = 121290667 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (121291697) 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, 1410326 + ... + 1410411.

It is an arithmetic number, because the mean of its divisors is an integer number (31028118).

Almost surely, 2^121291691 is an apocalyptic number.

121291691 is a deficient number, since it is larger than the sum of its proper divisors (2820781).

121291691 is an equidigital number, since it uses as much as digits as its factorization.

121291691 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2820780.

The product of its digits is 1944, while the sum is 32.

The square root of 121291691 is about 11013.2507008603. The cubic root of 121291691 is about 495.0058714401.

The spelling of 121291691 in words is "one hundred twenty-one million, two hundred ninety-one thousand, six hundred ninety-one".