21113545051 has 4 divisors (see below), whose sum is σ = 21188682504. Its totient is φ = 21038407600.

The previous prime is 21113545039. The next prime is 21113545081. The reversal of 21113545051 is 15054531112.

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 21113545051 - 2⁹ = 21113544539 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21113545081) 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, 37568305 + ... + 37568866.

It is an arithmetic number, because the mean of its divisors is an integer number (5297170626).

Almost surely, 2^21113545051 is an apocalyptic number.

21113545051 is a deficient number, since it is larger than the sum of its proper divisors (75137453).

21113545051 is an equidigital number, since it uses as much as digits as its factorization.

21113545051 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 75137452.

The product of its (nonzero) digits is 3000, while the sum is 28.

The spelling of 21113545051 in words is "twenty-one billion, one hundred thirteen million, five hundred forty-five thousand, fifty-one".