121021001001 has 24 divisors (see below), whose sum is σ = 175873089600. Its totient is φ = 80190336096.

The previous prime is 121021000951. The next prime is 121021001009. The reversal of 121021001001 is 100100120121.

It is a happy number.

It is not a de Polignac number, because 121021001001 - 2⁷ = 121021000873 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is not an unprimeable number, because it can be changed into a prime (121021001009) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1174311 + ... + 1273203.

It is an arithmetic number, because the mean of its divisors is an integer number (7328045400).

Almost surely, 2^121021001001 is an apocalyptic number.

It is an amenable number.

121021001001 is a deficient number, since it is larger than the sum of its proper divisors (54852088599).

121021001001 is a wasteful number, since it uses less digits than its factorization.

121021001001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 99725 (or 99722 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 9.

Adding to 121021001001 its reverse (100100120121), we get a palindrome (221121121122).

The spelling of 121021001001 in words is "one hundred twenty-one billion, twenty-one million, one thousand, one".