121276491821 has 4 divisors (see below), whose sum is σ = 121285767612. Its totient is φ = 121267216032.

The previous prime is 121276491773. The next prime is 121276491829. The reversal of 121276491821 is 128194672121.

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: 128194672121 = 63197 ⋅2028493.

It can be written as a sum of positive squares in 2 ways, for example, as 68821750921 + 52454740900 = 262339^2 + 229030^2 .

It is a cyclic number.

It is not a de Polignac number, because 121276491821 - 2¹⁸ = 121276229677 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 (121276491829) 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 in 3 ways as a sum of consecutive naturals, for example, 4618256 + ... + 4644441.

It is an arithmetic number, because the mean of its divisors is an integer number (30321441903).

Almost surely, 2^121276491821 is an apocalyptic number.

It is an amenable number.

121276491821 is a deficient number, since it is larger than the sum of its proper divisors (9275791).

121276491821 is an equidigital number, since it uses as much as digits as its factorization.

121276491821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9275790.

The product of its digits is 96768, while the sum is 44.

The spelling of 121276491821 in words is "one hundred twenty-one billion, two hundred seventy-six million, four hundred ninety-one thousand, eight hundred twenty-one".