121221231421 has 4 divisors (see below), whose sum is σ = 121222972000. Its totient is φ = 121219490844.

The previous prime is 121221231413. The next prime is 121221231433. The reversal of 121221231421 is 124132122121.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 124132122121 = 7 ⋅17733160303.

It is a cyclic number.

It is not a de Polignac number, because 121221231421 - 2³ = 121221231413 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 121221231392 and 121221231401.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121221231451) 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, 761271 + ... + 906628.

It is an arithmetic number, because the mean of its divisors is an integer number (30305743000).

Almost surely, 2^121221231421 is an apocalyptic number.

It is an amenable number.

121221231421 is a deficient number, since it is larger than the sum of its proper divisors (1740579).

121221231421 is an equidigital number, since it uses as much as digits as its factorization.

121221231421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1740578.

The product of its digits is 384, while the sum is 22.

Adding to 121221231421 its reverse (124132122121), we get a palindrome (245353353542).

The spelling of 121221231421 in words is "one hundred twenty-one billion, two hundred twenty-one million, two hundred thirty-one thousand, four hundred twenty-one".