21111145025 has 24 divisors (see below), whose sum is σ = 26276068224. Its totient is φ = 16825659200.

The previous prime is 21111145007. The next prime is 21111145031. The reversal of 21111145025 is 52054111112.

It is a happy number.

It is not a de Polignac number, because 21111145025 - 2¹² = 21111140929 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 14793362 + ... + 14794788.

It is an arithmetic number, because the mean of its divisors is an integer number (1094836176).

Almost surely, 2^21111145025 is an apocalyptic number.

21111145025 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21111145025 is a deficient number, since it is larger than the sum of its proper divisors (5164923199).

21111145025 is a wasteful number, since it uses less digits than its factorization.

21111145025 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3241 (or 3236 counting only the distinct ones).

The product of its (nonzero) digits is 400, while the sum is 23.

Adding to 21111145025 its reverse (52054111112), we get a palindrome (73165256137).

The spelling of 21111145025 in words is "twenty-one billion, one hundred eleven million, one hundred forty-five thousand, twenty-five".