21263044 has 12 divisors (see below), whose sum is σ = 40593168. Its totient is φ = 9665000.

The previous prime is 21263041. The next prime is 21263057. The reversal of 21263044 is 44036212.

It is a happy number.

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

It is not an unprimeable number, because it can be changed into a prime (21263041) 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, 241582 + ... + 241669.

It is an arithmetic number, because the mean of its divisors is an integer number (3382764).

Almost surely, 2^21263044 is an apocalyptic number.

It is an amenable number.

21263044 is a deficient number, since it is larger than the sum of its proper divisors (19330124).

21263044 is a wasteful number, since it uses less digits than its factorization.

21263044 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 483266 (or 483264 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 22.

The square root of 21263044 is about 4611.1868320423. The cubic root of 21263044 is about 277.0395752081.

Adding to 21263044 its reverse (44036212), we get a palindrome (65299256).

The spelling of 21263044 in words is "twenty-one million, two hundred sixty-three thousand, forty-four".