21113002051 has 4 divisors (see below), whose sum is σ = 21121146952. Its totient is φ = 21104857152.

The previous prime is 21113001991. The next prime is 21113002091. The reversal of 21113002051 is 15020031112.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21113002051 - 2¹¹ = 21113000003 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21113002091) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4068561 + ... + 4073746.

It is an arithmetic number, because the mean of its divisors is an integer number (5280286738).

Almost surely, 2^21113002051 is an apocalyptic number.

21113002051 is a deficient number, since it is larger than the sum of its proper divisors (8144901).

21113002051 is an equidigital number, since it uses as much as digits as its factorization.

21113002051 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8144900.

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

Adding to 21113002051 its reverse (15020031112), we get a palindrome (36133033163).

The spelling of 21113002051 in words is "twenty-one billion, one hundred thirteen million, two thousand, fifty-one".