21555546125 has 32 divisors (see below), whose sum is σ = 27507392640. Its totient is φ = 16860249600.

The previous prime is 21555546119. The next prime is 21555546139. The reversal of 21555546125 is 52164555512.

It is a de Polignac number, because none of the positive numbers 2^k-21555546125 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 995666 + ... + 1017084.

It is an arithmetic number, because the mean of its divisors is an integer number (859606020).

Almost surely, 2^21555546125 is an apocalyptic number.

21555546125 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21555546125 is a deficient number, since it is larger than the sum of its proper divisors (5951846515).

21555546125 is an equidigital number, since it uses as much as digits as its factorization.

21555546125 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21614 (or 21604 counting only the distinct ones).

The product of its digits is 300000, while the sum is 41.

The spelling of 21555546125 in words is "twenty-one billion, five hundred fifty-five million, five hundred forty-six thousand, one hundred twenty-five".