21356054400 has 192 divisors, whose sum is σ = 70441138800. Its totient is φ = 5686886400.

The previous prime is 21356054399. The next prime is 21356054413. The reversal of 21356054400 is 445065312.

It is a tau number, because it is divible by the number of its divisors (192).

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

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, 10261360 + ... + 10263440.

Almost surely, 2^21356054400 is an apocalyptic number.

21356054400 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 21356054400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35220569400).

21356054400 is an abundant number, since it is smaller than the sum of its proper divisors (49085084400).

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

21356054400 is a wasteful number, since it uses less digits than its factorization.

21356054400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3177 (or 3160 counting only the distinct ones).

The product of its (nonzero) digits is 14400, while the sum is 30.

The spelling of 21356054400 in words is "twenty-one billion, three hundred fifty-six million, fifty-four thousand, four hundred".