21123425051 has 8 divisors (see below), whose sum is σ = 21670778640. Its totient is φ = 20583044352.

The previous prime is 21123425003. The next prime is 21123425069. The reversal of 21123425051 is 15052432112.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21123425051 - 2²⁶ = 21056316187 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21123425051.

It is not an unprimeable number, because it can be changed into a prime (21123455051) 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 7 ways as a sum of consecutive naturals, for example, 1737086 + ... + 1749203.

It is an arithmetic number, because the mean of its divisors is an integer number (2708847330).

Almost surely, 2^21123425051 is an apocalyptic number.

21123425051 is a deficient number, since it is larger than the sum of its proper divisors (547353589).

21123425051 is an equidigital number, since it uses as much as digits as its factorization.

21123425051 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3486445.

The product of its (nonzero) digits is 2400, while the sum is 26.

Adding to 21123425051 its reverse (15052432112), we get a palindrome (36175857163).

The spelling of 21123425051 in words is "twenty-one billion, one hundred twenty-three million, four hundred twenty-five thousand, fifty-one".