21022002101 has 4 divisors (see below), whose sum is σ = 21024364332. Its totient is φ = 21019639872.

The previous prime is 21022002049. The next prime is 21022002109. The reversal of 21022002101 is 10120022012.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 4273759876 + 16748242225 = 65374^2 + 129415^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21022002101 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21022002109) 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, 1167716 + ... + 1185581.

It is an arithmetic number, because the mean of its divisors is an integer number (5256091083).

Almost surely, 2^21022002101 is an apocalyptic number.

It is an amenable number.

21022002101 is a deficient number, since it is larger than the sum of its proper divisors (2362231).

21022002101 is an equidigital number, since it uses as much as digits as its factorization.

21022002101 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2362230.

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

Adding to 21022002101 its reverse (10120022012), we get a palindrome (31142024113).

The spelling of 21022002101 in words is "twenty-one billion, twenty-two million, two thousand, one hundred one".