21210202001 has 8 divisors (see below), whose sum is σ = 21373065000. Its totient is φ = 21047612800.

The previous prime is 21210201989. The next prime is 21210202007. The reversal of 21210202001 is 10020201212.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 1144062976 + 20066139025 = 33824^2 + 141655^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21210202001 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21210202007) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 88451 + ... + 224151.

It is an arithmetic number, because the mean of its divisors is an integer number (2671633125).

Almost surely, 2^21210202001 is an apocalyptic number.

It is an amenable number.

21210202001 is a deficient number, since it is larger than the sum of its proper divisors (162862999).

21210202001 is a wasteful number, since it uses less digits than its factorization.

21210202001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 136899.

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

Adding to 21210202001 its reverse (10020201212), we get a palindrome (31230403213).

The spelling of 21210202001 in words is "twenty-one billion, two hundred ten million, two hundred two thousand, one".