21021012222001 has 4 divisors (see below), whose sum is σ = 22932013333104. Its totient is φ = 19110011110900.

The previous prime is 21021012221941. The next prime is 21021012222029. The reversal of 21021012222001 is 10022221012012.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21021012222001 - 2⁷ = 21021012221873 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21021012222701) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 955500555535 + ... + 955500555556.

It is an arithmetic number, because the mean of its divisors is an integer number (5733003333276).

Almost surely, 2^{21021012222001} is an apocalyptic number.

It is an amenable number.

21021012222001 is a deficient number, since it is larger than the sum of its proper divisors (1911001111103).

21021012222001 is a wasteful number, since it uses less digits than its factorization.

21021012222001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1911001111102.

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 21021012222001 its reverse (10022221012012), we get a palindrome (31043233234013).

The spelling of 21021012222001 in words is "twenty-one trillion, twenty-one billion, twelve million, two hundred twenty-two thousand, one".