21380403600 has 840 divisors, whose sum is σ = 86214615840. Its totient is φ = 5061242880.

The previous prime is 21380403557. The next prime is 21380403607. The reversal of 21380403600 is 630408312.

It is a happy number.

21380403600 is a `hidden beast` number, since 2 + 13 + 8 + 0 + 40 + 3 + 600 = 666.

It is a super-3 number, since 3×21380403600³ (a number of 32 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (21380403607) by changing a digit.

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 167 ways as a sum of consecutive naturals, for example, 94186687 + ... + 94186913.

Almost surely, 2^21380403600 is an apocalyptic number.

21380403600 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 21380403600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (43107307920).

21380403600 is an abundant number, since it is smaller than the sum of its proper divisors (64834212240).

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

21380403600 is a wasteful number, since it uses less digits than its factorization.

21380403600 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 299 (or 273 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 27.

The spelling of 21380403600 in words is "twenty-one billion, three hundred eighty million, four hundred three thousand, six hundred".