21740800 has 108 divisors (see below), whose sum is σ = 55760320. Its totient is φ = 8386560.

The previous prime is 21740791. The next prime is 21740801. The reversal of 21740800 is 804712.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21740801) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 275161 + ... + 275239.

Almost surely, 2^21740800 is an apocalyptic number.

21740800 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 21740800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27880160).

21740800 is an abundant number, since it is smaller than the sum of its proper divisors (34019520).

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

21740800 is an equidigital number, since it uses as much as digits as its factorization.

21740800 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 148 (or 129 counting only the distinct ones).

The product of its (nonzero) digits is 448, while the sum is 22.

The square root of 21740800 is about 4662.7030786873. The cubic root of 21740800 is about 279.0991455722.

The spelling of 21740800 in words is "twenty-one million, seven hundred forty thousand, eight hundred".