21413444 has 24 divisors (see below), whose sum is σ = 40548480. Its totient is φ = 9836064.

The previous prime is 21413443. The next prime is 21413449. The reversal of 21413444 is 44431412.

It is a happy number.

It is a super-2 number, since 2×21413444² = 917071167882272, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21413443) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11567 + ... + 13289.

It is an arithmetic number, because the mean of its divisors is an integer number (1689520).

Almost surely, 2^21413444 is an apocalyptic number.

It is an amenable number.

21413444 is a deficient number, since it is larger than the sum of its proper divisors (19135036).

21413444 is a wasteful number, since it uses less digits than its factorization.

21413444 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1979 (or 1977 counting only the distinct ones).

The product of its digits is 1536, while the sum is 23.

The square root of 21413444 is about 4627.4662613573. The cubic root of 21413444 is about 277.6912363061.

Adding to 21413444 its reverse (44431412), we get a palindrome (65844856).

The spelling of 21413444 in words is "twenty-one million, four hundred thirteen thousand, four hundred forty-four".