21002028201 has 72 divisors (see below), whose sum is σ = 39422859840. Its totient is φ = 10533821760.

The previous prime is 21002028163. The next prime is 21002028239. The reversal of 21002028201 is 10282020012.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21002028163) and next prime (21002028239).

It is not a de Polignac number, because 21002028201 - 2¹⁰ = 21002027177 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21002028251) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 173566 + ... + 268568.

It is an arithmetic number, because the mean of its divisors is an integer number (547539720).

Almost surely, 2^21002028201 is an apocalyptic number.

21002028201 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

21002028201 is a deficient number, since it is larger than the sum of its proper divisors (18420831639).

21002028201 is a wasteful number, since it uses less digits than its factorization.

21002028201 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 95067 (or 95053 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 18.

Adding to 21002028201 its reverse (10282020012), we get a palindrome (31284048213).

The spelling of 21002028201 in words is "twenty-one billion, two million, twenty-eight thousand, two hundred one".