21202102002001 has 4 divisors (see below), whose sum is σ = 21220332529392. Its totient is φ = 21183871474612.

The previous prime is 21202102001989. The next prime is 21202102002013. The reversal of 21202102002001 is 10020020120212.

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 an interprime number because it is at equal distance from previous prime (21202102001989) and next prime (21202102002013).

It is a cyclic number.

It is not a de Polignac number, because 21202102002001 - 2²¹ = 21202099904849 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21202102002031) 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, 9115261951 + ... + 9115264276.

It is an arithmetic number, because the mean of its divisors is an integer number (5305083132348).

Almost surely, 2^{21202102002001} is an apocalyptic number.

It is an amenable number.

21202102002001 is a deficient number, since it is larger than the sum of its proper divisors (18230527391).

21202102002001 is a wasteful number, since it uses less digits than its factorization.

21202102002001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18230527390.

The product of its (nonzero) digits is 32, while the sum is 13.

Adding to 21202102002001 its reverse (10020020120212), we get a palindrome (31222122122213).

The spelling of 21202102002001 in words is "twenty-one trillion, two hundred two billion, one hundred two million, two thousand, one".