21244750 has 16 divisors (see below), whose sum is σ = 39770640. Its totient is φ = 8497800.

The previous prime is 21244723. The next prime is 21244757. The reversal of 21244750 is 5744212.

It is a Harshad number since it is a multiple of its sum of digits (25).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21244757) 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 7 ways as a sum of consecutive naturals, for example, 42240 + ... + 42739.

It is an arithmetic number, because the mean of its divisors is an integer number (2485665).

Almost surely, 2^21244750 is an apocalyptic number.

21244750 is a deficient number, since it is larger than the sum of its proper divisors (18525890).

21244750 is an equidigital number, since it uses as much as digits as its factorization.

21244750 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 84996 (or 84986 counting only the distinct ones).

The product of its (nonzero) digits is 2240, while the sum is 25.

The square root of 21244750 is about 4609.2027510189. The cubic root of 21244750 is about 276.9601006014.

Adding to 21244750 its reverse (5744212), we get a palindrome (26988962).

The spelling of 21244750 in words is "twenty-one million, two hundred forty-four thousand, seven hundred fifty".