21549224 has 8 divisors (see below), whose sum is σ = 40404810. Its totient is φ = 10774608.

The previous prime is 21549221. The next prime is 21549257. The reversal of 21549224 is 42294512.

It can be written as a sum of positive squares in only one way, i.e., 12124324 + 9424900 = 3482^2 + 3070^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is a super-3 number, since 3×21549224³ (a number of 23 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (21549221) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1346819 + ... + 1346834.

Almost surely, 2^21549224 is an apocalyptic number.

It is an amenable number.

21549224 is a deficient number, since it is larger than the sum of its proper divisors (18855586).

21549224 is a wasteful number, since it uses less digits than its factorization.

21549224 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2693659 (or 2693655 counting only the distinct ones).

The product of its digits is 5760, while the sum is 29.

The square root of 21549224 is about 4642.1141735205. The cubic root of 21549224 is about 278.2769353581.

The spelling of 21549224 in words is "twenty-one million, five hundred forty-nine thousand, two hundred twenty-four".