21425124043 has 4 divisors (see below), whose sum is σ = 21425590768. Its totient is φ = 21424657320.

The previous prime is 21425124011. The next prime is 21425124121. The reversal of 21425124043 is 34042152412.

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 21425124043 - 2⁵ = 21425124011 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21425121043) 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, 155943 + ... + 259168.

It is an arithmetic number, because the mean of its divisors is an integer number (5356397692).

Almost surely, 2^21425124043 is an apocalyptic number.

21425124043 is a deficient number, since it is larger than the sum of its proper divisors (466725).

21425124043 is an equidigital number, since it uses as much as digits as its factorization.

21425124043 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 466724.

The product of its (nonzero) digits is 7680, while the sum is 28.

Adding to 21425124043 its reverse (34042152412), we get a palindrome (55467276455).

The spelling of 21425124043 in words is "twenty-one billion, four hundred twenty-five million, one hundred twenty-four thousand, forty-three".