121221001001 has 4 divisors (see below), whose sum is σ = 125131355904. Its totient is φ = 117310646100.

The previous prime is 121221000997. The next prime is 121221001003. The reversal of 121221001001 is 100100122121.

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 121221001001 - 2² = 121221000997 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (121221001003) 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, 1955177405 + ... + 1955177466.

It is an arithmetic number, because the mean of its divisors is an integer number (31282838976).

Almost surely, 2^121221001001 is an apocalyptic number.

It is an amenable number.

121221001001 is a deficient number, since it is larger than the sum of its proper divisors (3910354903).

121221001001 is an equidigital number, since it uses as much as digits as its factorization.

121221001001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3910354902.

The product of its (nonzero) digits is 8, while the sum is 11.

Adding to 121221001001 its reverse (100100122121), we get a palindrome (221321123122).

The spelling of 121221001001 in words is "one hundred twenty-one billion, two hundred twenty-one million, one thousand, one".