121421155421 has 4 divisors (see below), whose sum is σ = 122884060992. Its totient is φ = 119958249852.

The previous prime is 121421155409. The next prime is 121421155423. The reversal of 121421155421 is 124551124121.

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.

It is a cyclic number.

It is not a de Polignac number, because 121421155421 - 2¹⁰ = 121421154397 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 (121421155423) 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, 731452661 + ... + 731452826.

It is an arithmetic number, because the mean of its divisors is an integer number (30721015248).

Almost surely, 2^121421155421 is an apocalyptic number.

It is an amenable number.

121421155421 is a deficient number, since it is larger than the sum of its proper divisors (1462905571).

121421155421 is an equidigital number, since it uses as much as digits as its factorization.

121421155421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1462905570.

The product of its digits is 3200, while the sum is 29.

Adding to 121421155421 its reverse (124551124121), we get a palindrome (245972279542).

The spelling of 121421155421 in words is "one hundred twenty-one billion, four hundred twenty-one million, one hundred fifty-five thousand, four hundred twenty-one".