21221121201 has 16 divisors (see below), whose sum is σ = 32792398848. Its totient is φ = 11955560400.

The previous prime is 21221121167. The next prime is 21221121241. The reversal of 21221121201 is 10212112212.

It is not a de Polignac number, because 21221121201 - 2¹³ = 21221113009 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21221121241) 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, 7114915 + ... + 7117896.

It is an arithmetic number, because the mean of its divisors is an integer number (2049524928).

Almost surely, 2^21221121201 is an apocalyptic number.

21221121201 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

21221121201 is a deficient number, since it is larger than the sum of its proper divisors (11571277647).

21221121201 is a wasteful number, since it uses less digits than its factorization.

21221121201 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14232892.

The product of its (nonzero) digits is 32, while the sum is 15.

Adding to 21221121201 its reverse (10212112212), we get a palindrome (31433233413).

The spelling of 21221121201 in words is "twenty-one billion, two hundred twenty-one million, one hundred twenty-one thousand, two hundred one".