21201140121 has 24 divisors (see below), whose sum is σ = 33333875424. Its totient is φ = 11948973120.

The previous prime is 21201140087. The next prime is 21201140137. The reversal of 21201140121 is 12104110212.

It is not a de Polignac number, because 21201140121 - 2¹³ = 21201131929 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21201140121.

It is not an unprimeable number, because it can be changed into a prime (21201140141) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 977115 + ... + 998576.

It is an arithmetic number, because the mean of its divisors is an integer number (1388911476).

Almost surely, 2^21201140121 is an apocalyptic number.

21201140121 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

21201140121 is a deficient number, since it is larger than the sum of its proper divisors (12132735303).

21201140121 is a wasteful number, since it uses less digits than its factorization.

21201140121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1975781 (or 1975774 counting only the distinct ones).

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

Adding to 21201140121 its reverse (12104110212), we get a palindrome (33305250333).

The spelling of 21201140121 in words is "twenty-one billion, two hundred one million, one hundred forty thousand, one hundred twenty-one".