21104021001 has 16 divisors (see below), whose sum is σ = 33195880448. Its totient is φ = 11670426000.

The previous prime is 21104020999. The next prime is 21104021009. The reversal of 21104021001 is 10012040112.

It is a happy number.

It is not a de Polignac number, because 21104021001 - 2¹ = 21104020999 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21104021009) 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, 16208275 + ... + 16209576.

It is an arithmetic number, because the mean of its divisors is an integer number (2074742528).

Almost surely, 2^21104021001 is an apocalyptic number.

21104021001 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

21104021001 is a deficient number, since it is larger than the sum of its proper divisors (12091859447).

21104021001 is a wasteful number, since it uses less digits than its factorization.

21104021001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32417892.

The product of its (nonzero) digits is 16, while the sum is 12.

Adding to 21104021001 its reverse (10012040112), we get a palindrome (31116061113).

The spelling of 21104021001 in words is "twenty-one billion, one hundred four million, twenty-one thousand, one".