21033221001 has 12 divisors (see below), whose sum is σ = 30367491408. Its totient is φ = 12943520304.

The previous prime is 21033220997. The next prime is 21033221003. The reversal of 21033221001 is 10012233012.

It is not a de Polignac number, because 21033221001 - 2² = 21033220997 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21033221003) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 20742315 + ... + 20743328.

It is an arithmetic number, because the mean of its divisors is an integer number (2530624284).

Almost surely, 2^21033221001 is an apocalyptic number.

It is an amenable number.

21033221001 is a deficient number, since it is larger than the sum of its proper divisors (9334270407).

21033221001 is a wasteful number, since it uses less digits than its factorization.

21033221001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41485672 (or 41485659 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 15.

Adding to 21033221001 its reverse (10012233012), we get a palindrome (31045454013).

The spelling of 21033221001 in words is "twenty-one billion, thirty-three million, two hundred twenty-one thousand, one".