21700244 has 12 divisors (see below), whose sum is σ = 38136000. Its totient is φ = 10804248.

The previous prime is 21700243. The next prime is 21700253. The reversal of 21700244 is 44200712.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21700243) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10394 + ... + 12305.

It is an arithmetic number, because the mean of its divisors is an integer number (3178000).

Almost surely, 2^21700244 is an apocalyptic number.

It is an amenable number.

21700244 is a deficient number, since it is larger than the sum of its proper divisors (16435756).

21700244 is a wasteful number, since it uses less digits than its factorization.

21700244 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22942 (or 22940 counting only the distinct ones).

The product of its (nonzero) digits is 448, while the sum is 20.

The square root of 21700244 is about 4658.3520691335. The cubic root of 21700244 is about 278.9254906527.

Adding to 21700244 its reverse (44200712), we get a palindrome (65900956).

The spelling of 21700244 in words is "twenty-one million, seven hundred thousand, two hundred forty-four".