21144266 has 48 divisors (see below), whose sum is σ = 38579328. Its totient is φ = 8682960.

The previous prime is 21144259. The next prime is 21144269. The reversal of 21144266 is 66244112.

It is a Harshad number since it is a multiple of its sum of digits (26).

It is not an unprimeable number, because it can be changed into a prime (21144269) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 449855 + ... + 449901.

It is an arithmetic number, because the mean of its divisors is an integer number (803736).

Almost surely, 2^21144266 is an apocalyptic number.

21144266 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

21144266 is a deficient number, since it is larger than the sum of its proper divisors (17435062).

21144266 is a wasteful number, since it uses less digits than its factorization.

21144266 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 108 (or 73 counting only the distinct ones).

The product of its digits is 2304, while the sum is 26.

The square root of 21144266 is about 4598.2894645727. The cubic root of 21144266 is about 276.5227525267.

Adding to 21144266 its reverse (66244112), we get a palindrome (87388378).

The spelling of 21144266 in words is "twenty-one million, one hundred forty-four thousand, two hundred sixty-six".