21256727100 has 72 divisors (see below), whose sum is σ = 70288917888. Its totient is φ = 4858680000.

The previous prime is 21256727059. The next prime is 21256727123. The reversal of 21256727100 is 172765212.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 5059026 + ... + 5063225.

Almost surely, 2^21256727100 is an apocalyptic number.

21256727100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21256727100 is an abundant number, since it is smaller than the sum of its proper divisors (49032190788).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21256727100 is a wasteful number, since it uses less digits than its factorization.

21256727100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10122275 (or 10122268 counting only the distinct ones).

The product of its (nonzero) digits is 11760, while the sum is 33.

The spelling of 21256727100 in words is "twenty-one billion, two hundred fifty-six million, seven hundred twenty-seven thousand, one hundred".