21120202001 has 4 divisors (see below), whose sum is σ = 22231791600. Its totient is φ = 20008612404.

The previous prime is 21120201929. The next prime is 21120202003. The reversal of 21120202001 is 10020202112.

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 21120202001 - 2²⁶ = 21053093137 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21120202003) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 555794771 + ... + 555794808.

It is an arithmetic number, because the mean of its divisors is an integer number (5557947900).

Almost surely, 2^21120202001 is an apocalyptic number.

It is an amenable number.

21120202001 is a deficient number, since it is larger than the sum of its proper divisors (1111589599).

21120202001 is a wasteful number, since it uses less digits than its factorization.

21120202001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1111589598.

The product of its (nonzero) digits is 16, while the sum is 11.

Adding to 21120202001 its reverse (10020202112), we get a palindrome (31140404113).

The spelling of 21120202001 in words is "twenty-one billion, one hundred twenty million, two hundred two thousand, one".