21444146 has 4 divisors (see below), whose sum is σ = 32166222. Its totient is φ = 10722072.

The previous prime is 21444139. The next prime is 21444149. The reversal of 21444146 is 64144412.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 15249025 + 6195121 = 3905^2 + 2489^2 .

It is not an unprimeable number, because it can be changed into a prime (21444149) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5361035 + ... + 5361038.

Almost surely, 2^21444146 is an apocalyptic number.

21444146 is a deficient number, since it is larger than the sum of its proper divisors (10722076).

21444146 is a wasteful number, since it uses less digits than its factorization.

21444146 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10722075.

The product of its digits is 3072, while the sum is 26.

The square root of 21444146 is about 4630.7824392860. The cubic root of 21444146 is about 277.8238882505.

Adding to 21444146 its reverse (64144412), we get a palindrome (85588558).

The spelling of 21444146 in words is "twenty-one million, four hundred forty-four thousand, one hundred forty-six".