21101121001 has 8 divisors (see below), whose sum is σ = 21202420680. Its totient is φ = 20999991168.

The previous prime is 21101120939. The next prime is 21101121029. The reversal of 21101121001 is 10012110112.

It can be written as a sum of positive squares in 4 ways, for example, as 808833600 + 20292287401 = 28440^2 + 142451^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21101121001 - 2¹⁵ = 21101088233 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21101121071) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 210195 + ... + 293911.

It is an arithmetic number, because the mean of its divisors is an integer number (2650302585).

Almost surely, 2^21101121001 is an apocalyptic number.

It is an amenable number.

21101121001 is a deficient number, since it is larger than the sum of its proper divisors (101299679).

21101121001 is an equidigital number, since it uses as much as digits as its factorization.

21101121001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 84923.

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

Adding to 21101121001 its reverse (10012110112), we get a palindrome (31113231113).

It can be divided in two parts, 2110112 and 1001, that multiplied together give a palindrome (2112222112).

The spelling of 21101121001 in words is "twenty-one billion, one hundred one million, one hundred twenty-one thousand, one".