21349785600 has 1176 divisors, whose sum is σ = 93257671752. Its totient is φ = 4777574400.

The previous prime is 21349785599. The next prime is 21349785601. The reversal of 21349785600 is 658794312.

21349785600 is a `hidden beast` number, since 2 + 1 + 34 + 9 + 7 + 8 + 5 + 600 = 666.

It is an interprime number because it is at equal distance from previous prime (21349785599) and next prime (21349785601).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21349785601) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 83 ways as a sum of consecutive naturals, for example, 1642291194 + ... + 1642291206.

It is a 1-persistent number, because it is pandigital, but 2⋅21349785600 = 42699571200 is not.

Almost surely, 2^21349785600 is an apocalyptic number.

21349785600 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 21349785600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (46628835876).

21349785600 is an abundant number, since it is smaller than the sum of its proper divisors (71907886152).

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

21349785600 is an equidigital number, since it uses as much as digits as its factorization.

21349785600 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 78 (or 34 counting only the distinct ones).

The product of its (nonzero) digits is 362880, while the sum is 45.

The spelling of 21349785600 in words is "twenty-one billion, three hundred forty-nine million, seven hundred eighty-five thousand, six hundred".