21000102201 has 20 divisors (see below), whose sum is σ = 33783641892. Its totient is φ = 12923139168.

The previous prime is 21000102197. The next prime is 21000102223. The reversal of 21000102201 is 10220100012.

It can be written as a sum of positive squares in 2 ways, for example, as 10547084601 + 10453017600 = 102699^2 + 102240^2 .

It is not a de Polignac number, because 21000102201 - 2² = 21000102197 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 (21000102281) 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, 9970506 + ... + 9972611.

Almost surely, 2^21000102201 is an apocalyptic number.

It is an amenable number.

21000102201 is a deficient number, since it is larger than the sum of its proper divisors (12783539691).

21000102201 is a wasteful number, since it uses less digits than its factorization.

21000102201 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19943142 (or 19943133 counting only the distinct ones).

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

Adding to 21000102201 its reverse (10220100012), we get a palindrome (31220202213).

It can be divided in two parts, 21000 and 102201, that added together give a square (123201 = 351²).

The spelling of 21000102201 in words is "twenty-one billion, one hundred two thousand, two hundred one".