21123410525 has 12 divisors (see below), whose sum is σ = 29934890592. Its totient is φ = 14484624240.

The previous prime is 21123410507. The next prime is 21123410527. The reversal of 21123410525 is 52501432112.

It is not a de Polignac number, because 21123410525 - 2²⁸ = 20854975069 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21123410494 and 21123410503.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21123410527) 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 11 ways as a sum of consecutive naturals, for example, 60352427 + ... + 60352776.

It is an arithmetic number, because the mean of its divisors is an integer number (2494574216).

Almost surely, 2^21123410525 is an apocalyptic number.

21123410525 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21123410525 is a deficient number, since it is larger than the sum of its proper divisors (8811480067).

21123410525 is a wasteful number, since it uses less digits than its factorization.

21123410525 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 120705220 (or 120705215 counting only the distinct ones).

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

Adding to 21123410525 its reverse (52501432112), we get a palindrome (73624842637).

The spelling of 21123410525 in words is "twenty-one billion, one hundred twenty-three million, four hundred ten thousand, five hundred twenty-five".