21000021201 has 20 divisors (see below), whose sum is σ = 31374961200. Its totient is φ = 13997979576.

The previous prime is 21000021197. The next prime is 21000021221. The reversal of 21000021201 is 10212000012.

It is not a de Polignac number, because 21000021201 - 2² = 21000021197 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 (21000021221) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 719470 + ... + 748088.

It is an arithmetic number, because the mean of its divisors is an integer number (1568748060).

Almost surely, 2^21000021201 is an apocalyptic number.

It is an amenable number.

21000021201 is a deficient number, since it is larger than the sum of its proper divisors (10374939999).

21000021201 is an equidigital number, since it uses as much as digits as its factorization.

21000021201 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 37690 (or 37681 counting only the distinct ones).

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

Adding to 21000021201 its reverse (10212000012), we get a palindrome (31212021213).

The spelling of 21000021201 in words is "twenty-one billion, twenty-one thousand, two hundred one".