121946765491 has 4 divisors (see below), whose sum is σ = 126151826400. Its totient is φ = 117741704584.

The previous prime is 121946765443. The next prime is 121946765503. The reversal of 121946765491 is 194567649121.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 194567649121 = 67 ⋅2903994763.

It is a cyclic number.

It is not a de Polignac number, because 121946765491 - 2²⁵ = 121913211059 is a prime.

It is a super-2 number, since 2×121946765491² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (121946765441) 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, 2102530411 + ... + 2102530468.

It is an arithmetic number, because the mean of its divisors is an integer number (31537956600).

Almost surely, 2^121946765491 is an apocalyptic number.

121946765491 is a deficient number, since it is larger than the sum of its proper divisors (4205060909).

121946765491 is an equidigital number, since it uses as much as digits as its factorization.

121946765491 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4205060908.

The product of its digits is 3265920, while the sum is 55.

The spelling of 121946765491 in words is "one hundred twenty-one billion, nine hundred forty-six million, seven hundred sixty-five thousand, four hundred ninety-one".