21121221201 has 8 divisors (see below), whose sum is σ = 28184773344. Its totient is φ = 14069241600.

The previous prime is 21121221193. The next prime is 21121221221. The reversal of 21121221201 is 10212212112.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21121221201 - 2³ = 21121221193 is a prime.

It is a super-2 number, since 2×21121221201² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21121221221) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2888875 + ... + 2896176.

It is an arithmetic number, because the mean of its divisors is an integer number (3523096668).

Almost surely, 2^21121221201 is an apocalyptic number.

It is an amenable number.

21121221201 is a deficient number, since it is larger than the sum of its proper divisors (7063552143).

21121221201 is a wasteful number, since it uses less digits than its factorization.

21121221201 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5786271.

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

Adding to 21121221201 its reverse (10212212112), we get a palindrome (31333433313).

The spelling of 21121221201 in words is "twenty-one billion, one hundred twenty-one million, two hundred twenty-one thousand, two hundred one".