21022121001 has 64 divisors (see below), whose sum is σ = 34214400000. Its totient is φ = 11207725056.

The previous prime is 21022120991. The next prime is 21022121011. The reversal of 21022121001 is 10012122012.

It is an interprime number because it is at equal distance from previous prime (21022120991) and next prime (21022121011).

It is not a de Polignac number, because 21022121001 - 2³³ = 12432186409 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21022121011) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 35450161 + ... + 35450753.

It is an arithmetic number, because the mean of its divisors is an integer number (534600000).

Almost surely, 2^21022121001 is an apocalyptic number.

21022121001 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

21022121001 is a deficient number, since it is larger than the sum of its proper divisors (13192278999).

21022121001 is a wasteful number, since it uses less digits than its factorization.

21022121001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1318.

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

Adding to 21022121001 its reverse (10012122012), we get a palindrome (31034243013).

The spelling of 21022121001 in words is "twenty-one billion, twenty-two million, one hundred twenty-one thousand, one".