21401444 has 12 divisors (see below), whose sum is σ = 38323824. Its totient is φ = 10451784.

The previous prime is 21401441. The next prime is 21401447. The reversal of 21401444 is 44410412.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21401441) and next prime (21401447).

It is not an unprimeable number, because it can be changed into a prime (21401441) 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, 62042 + ... + 62385.

It is an arithmetic number, because the mean of its divisors is an integer number (3193652).

Almost surely, 2^21401444 is an apocalyptic number.

It is an amenable number.

21401444 is a deficient number, since it is larger than the sum of its proper divisors (16922380).

21401444 is a wasteful number, since it uses less digits than its factorization.

21401444 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 124474 (or 124472 counting only the distinct ones).

The product of its (nonzero) digits is 512, while the sum is 20.

The square root of 21401444 is about 4626.1694737655. The cubic root of 21401444 is about 277.6393542968.

Adding to 21401444 its reverse (44410412), we get a palindrome (65811856).

The spelling of 21401444 in words is "twenty-one million, four hundred one thousand, four hundred forty-four".