921221020221001 has 4 divisors (see below), whose sum is σ = 921221905539600. Its totient is φ = 921220134902404.

The previous prime is 921221020220983. The next prime is 921221020221037. The reversal of 921221020221001 is 100122020122129.

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 921221020221001 - 2¹¹ = 921221020218953 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (921221020221301) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 441096631 + ... + 443180188.

It is an arithmetic number, because the mean of its divisors is an integer number (230305476384900).

Almost surely, 2^{921221020221001} is an apocalyptic number.

It is an amenable number.

921221020221001 is a deficient number, since it is larger than the sum of its proper divisors (885318599).

921221020221001 is a wasteful number, since it uses less digits than its factorization.

921221020221001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 885318598.

The product of its (nonzero) digits is 576, while the sum is 25.

The spelling of 921221020221001 in words is "nine hundred twenty-one trillion, two hundred twenty-one billion, twenty million, two hundred twenty-one thousand, one".