21221000121 has 8 divisors (see below), whose sum is σ = 29207398144. Its totient is φ = 13690967760.

The previous prime is 21221000083. The next prime is 21221000131. The reversal of 21221000121 is 12100012212.

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

It is not a de Polignac number, because 21221000121 - 2⁹ = 21220999609 is a prime.

It is a super-2 number, since 2×21221000121² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21221000097 and 21221000106.

It is not an unprimeable number, because it can be changed into a prime (21221000131) 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, 114091306 + ... + 114091491.

It is an arithmetic number, because the mean of its divisors is an integer number (3650924768).

Almost surely, 2^21221000121 is an apocalyptic number.

It is an amenable number.

21221000121 is a deficient number, since it is larger than the sum of its proper divisors (7986398023).

21221000121 is a wasteful number, since it uses less digits than its factorization.

21221000121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 228182831.

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

Adding to 21221000121 its reverse (12100012212), we get a palindrome (33321012333).

The spelling of 21221000121 in words is "twenty-one billion, two hundred twenty-one million, one hundred twenty-one", and thus it is an aban number.