21144442 has 16 divisors (see below), whose sum is σ = 34992000. Its totient is φ = 9502240.

The previous prime is 21144437. The next prime is 21144467. The reversal of 21144442 is 24444112.

It is a Harshad number since it is a multiple of its sum of digits (22).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3442 + ... + 7357.

It is an arithmetic number, because the mean of its divisors is an integer number (2187000).

Almost surely, 2^21144442 is an apocalyptic number.

21144442 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

21144442 is a deficient number, since it is larger than the sum of its proper divisors (13847558).

21144442 is a wasteful number, since it uses less digits than its factorization.

21144442 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10901.

The product of its digits is 1024, while the sum is 22.

The square root of 21144442 is about 4598.3086020840. The cubic root of 21144442 is about 276.5235197618.

Adding to 21144442 its reverse (24444112), we get a palindrome (45588554).

It can be divided in two parts, 2114 and 4442, that added together give a palindrome (6556).

The spelling of 21144442 in words is "twenty-one million, one hundred forty-four thousand, four hundred forty-two".