21101854400 has 168 divisors, whose sum is σ = 57963474624. Its totient is φ = 7494681600.

The previous prime is 21101854381. The next prime is 21101854421. The reversal of 21101854400 is 445810112.

It is a self number, because there is not a number n which added to its sum of digits gives 21101854400.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 742859 + ... + 770741.

Almost surely, 2^21101854400 is an apocalyptic number.

21101854400 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21101854400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28981737312).

21101854400 is an abundant number, since it is smaller than the sum of its proper divisors (36861620224).

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

21101854400 is a wasteful number, since it uses less digits than its factorization.

21101854400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27959 (or 27944 counting only the distinct ones).

The product of its (nonzero) digits is 1280, while the sum is 26.

The spelling of 21101854400 in words is "twenty-one billion, one hundred one million, eight hundred fifty-four thousand, four hundred".