21002100201 has 8 divisors (see below), whose sum is σ = 31114222560. Its totient is φ = 14001400116.

The previous prime is 21002100199. The next prime is 21002100221. The reversal of 21002100201 is 10200120012.

It is not a de Polignac number, because 21002100201 - 2¹ = 21002100199 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is not an unprimeable number, because it can be changed into a prime (21002100221) 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, 388927755 + ... + 388927808.

It is an arithmetic number, because the mean of its divisors is an integer number (3889277820).

Almost surely, 2^21002100201 is an apocalyptic number.

It is an amenable number.

21002100201 is a deficient number, since it is larger than the sum of its proper divisors (10112122359).

21002100201 is an equidigital number, since it uses as much as digits as its factorization.

21002100201 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 777855572 (or 777855566 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 9.

Adding to 21002100201 its reverse (10200120012), we get a palindrome (31202220213).

The spelling of 21002100201 in words is "twenty-one billion, two million, one hundred thousand, two hundred one".