21001020201 has 48 divisors (see below), whose sum is σ = 36226008000. Its totient is φ = 11989385856.

The previous prime is 21001020197. The next prime is 21001020223. The reversal of 21001020201 is 10202010012.

It is not a de Polignac number, because 21001020201 - 2² = 21001020197 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 (21001020301) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1531825 + ... + 1545473.

It is an arithmetic number, because the mean of its divisors is an integer number (754708500).

Almost surely, 2^21001020201 is an apocalyptic number.

21001020201 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

21001020201 is a deficient number, since it is larger than the sum of its proper divisors (15224987799).

21001020201 is a wasteful number, since it uses less digits than its factorization.

21001020201 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14835 (or 14822 counting only the distinct ones).

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

Adding to 21001020201 its reverse (10202010012), we get a palindrome (31203030213).

The spelling of 21001020201 in words is "twenty-one billion, one million, twenty thousand, two hundred one".