21001212201 has 16 divisors (see below), whose sum is σ = 28116543488. Its totient is φ = 13943437200.

The previous prime is 21001212181. The next prime is 21001212233. The reversal of 21001212201 is 10221210012.

It is a de Polignac number, because none of the positive numbers 2^k-21001212201 is a prime.

It is a super-2 number, since 2×21001212201² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21001252201) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 949296 + ... + 971166.

It is an arithmetic number, because the mean of its divisors is an integer number (1757283968).

Almost surely, 2^21001212201 is an apocalyptic number.

It is an amenable number.

21001212201 is a deficient number, since it is larger than the sum of its proper divisors (7115331287).

21001212201 is a wasteful number, since it uses less digits than its factorization.

21001212201 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23172.

The product of its (nonzero) digits is 16, while the sum is 12.

Adding to 21001212201 its reverse (10221210012), we get a palindrome (31222422213).

The spelling of 21001212201 in words is "twenty-one billion, one million, two hundred twelve thousand, two hundred one".