21162744 has 48 divisors (see below), whose sum is σ = 57681000. Its totient is φ = 7009344.

The previous prime is 21162727. The next prime is 21162749. The reversal of 21162744 is 44726112.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21162749) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 11607 + ... + 13305.

Almost surely, 2^21162744 is an apocalyptic number.

21162744 is a gapful number since it is divisible by the number (24) 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 21162744, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28840500).

21162744 is an abundant number, since it is smaller than the sum of its proper divisors (36518256).

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

21162744 is a wasteful number, since it uses less digits than its factorization.

21162744 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1884 (or 1877 counting only the distinct ones).

The product of its digits is 2688, while the sum is 27.

The square root of 21162744 is about 4600.2982512007. The cubic root of 21162744 is about 276.6032802644.

Adding to 21162744 its reverse (44726112), we get a palindrome (65888856).

The spelling of 21162744 in words is "twenty-one million, one hundred sixty-two thousand, seven hundred forty-four".