21423044 has 6 divisors (see below), whose sum is σ = 37490334. Its totient is φ = 10711520.

The previous prime is 21423019. The next prime is 21423053. The reversal of 21423044 is 44032412.

It can be written as a sum of positive squares in only one way, i.e., 18318400 + 3104644 = 4280^2 + 1762^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2677877 + ... + 2677884.

It is an arithmetic number, because the mean of its divisors is an integer number (6248389).

Almost surely, 2^21423044 is an apocalyptic number.

It is an amenable number.

21423044 is a deficient number, since it is larger than the sum of its proper divisors (16067290).

21423044 is a wasteful number, since it uses less digits than its factorization.

21423044 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5355765 (or 5355763 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 20.

The square root of 21423044 is about 4628.5034298356. The cubic root of 21423044 is about 277.7327279594.

Adding to 21423044 its reverse (44032412), we get a palindrome (65455456).

The spelling of 21423044 in words is "twenty-one million, four hundred twenty-three thousand, forty-four".