21002051113 has 4 divisors (see below), whose sum is σ = 21052175760. Its totient is φ = 20951926468.

The previous prime is 21002051101. The next prime is 21002051117. The reversal of 21002051113 is 31115020012.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21002051113 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21002051117) 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 3 ways as a sum of consecutive naturals, for example, 25061695 + ... + 25062532.

It is an arithmetic number, because the mean of its divisors is an integer number (5263043940).

Almost surely, 2^21002051113 is an apocalyptic number.

It is an amenable number.

21002051113 is a deficient number, since it is larger than the sum of its proper divisors (50124647).

21002051113 is an equidigital number, since it uses as much as digits as its factorization.

21002051113 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 50124646.

The product of its (nonzero) digits is 60, while the sum is 16.

Adding to 21002051113 its reverse (31115020012), we get a palindrome (52117071125).

The spelling of 21002051113 in words is "twenty-one billion, two million, fifty-one thousand, one hundred thirteen".