21420121113 has 16 divisors (see below), whose sum is σ = 31965149760. Its totient is φ = 14175844128.

The previous prime is 21420121097. The next prime is 21420121153. The reversal of 21420121113 is 31112102412.

21420121113 is a `hidden beast` number, since 21 + 420 + 1 + 211 + 13 = 666.

It is not a de Polignac number, because 21420121113 - 2⁴ = 21420121097 is a prime.

It is a super-3 number, since 3×21420121113³ (a number of 32 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (21420121153) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2891695 + ... + 2899092.

It is an arithmetic number, because the mean of its divisors is an integer number (1997821860).

Almost surely, 2^21420121113 is an apocalyptic number.

It is an amenable number.

21420121113 is a deficient number, since it is larger than the sum of its proper divisors (10545028647).

21420121113 is a wasteful number, since it uses less digits than its factorization.

21420121113 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5790933 (or 5790927 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 18.

Adding to 21420121113 its reverse (31112102412), we get a palindrome (52532223525).

The spelling of 21420121113 in words is "twenty-one billion, four hundred twenty million, one hundred twenty-one thousand, one hundred thirteen".