21000121101001 has 16 divisors (see below), whose sum is σ = 24054179385600. Its totient is φ = 17959575029760.

The previous prime is 21000121100971. The next prime is 21000121101041. The reversal of 21000121101001 is 10010112100012.

It is not a de Polignac number, because 21000121101001 - 2¹¹ = 21000121098953 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21000121101041) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 254595196 + ... + 254677666.

It is an arithmetic number, because the mean of its divisors is an integer number (1503386211600).

Almost surely, 2^{21000121101001} is an apocalyptic number.

It is an amenable number.

21000121101001 is a deficient number, since it is larger than the sum of its proper divisors (3054058284599).

21000121101001 is an equidigital number, since it uses as much as digits as its factorization.

21000121101001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 163944.

The product of its (nonzero) digits is 4, while the sum is 10.

Adding to 21000121101001 its reverse (10010112100012), we get a palindrome (31010233201013).

The spelling of 21000121101001 in words is "twenty-one trillion, one hundred twenty-one million, one hundred one thousand, one".