21345750 has 96 divisors (see below), whose sum is σ = 59136480. Its totient is φ = 5553600.

The previous prime is 21345733. The next prime is 21345757. The reversal of 21345750 is 5754312.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21345757) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 119161 + ... + 119339.

It is an arithmetic number, because the mean of its divisors is an integer number (616005).

Almost surely, 2^21345750 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21345750, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29568240).

21345750 is an abundant number, since it is smaller than the sum of its proper divisors (37790730).

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

21345750 is a wasteful number, since it uses less digits than its factorization.

21345750 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 255 (or 242 counting only the distinct ones).

The product of its (nonzero) digits is 4200, while the sum is 27.

The square root of 21345750 is about 4620.1461015860. The cubic root of 21345750 is about 277.3983070283.

The spelling of 21345750 in words is "twenty-one million, three hundred forty-five thousand, seven hundred fifty".