21122001021 has 8 divisors (see below), whose sum is σ = 30722910624. Its totient is φ = 12801212720.

The previous prime is 21122001007. The next prime is 21122001029. The reversal of 21122001021 is 12010022112.

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 21122001021 - 2⁹ = 21122000509 is a prime.

It is a super-2 number, since 2×21122001021² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21122000988 and 21122001006.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21122001029) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 320030286 + ... + 320030351.

It is an arithmetic number, because the mean of its divisors is an integer number (3840363828).

Almost surely, 2^21122001021 is an apocalyptic number.

It is an amenable number.

21122001021 is a deficient number, since it is larger than the sum of its proper divisors (9600909603).

21122001021 is a wasteful number, since it uses less digits than its factorization.

21122001021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 640060651.

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

Adding to 21122001021 its reverse (12010022112), we get a palindrome (33132023133).

The spelling of 21122001021 in words is "twenty-one billion, one hundred twenty-two million, one thousand, twenty-one".