21044505 has 32 divisors (see below), whose sum is σ = 35094528. Its totient is φ = 10756800.

The previous prime is 21044479. The next prime is 21044531. The reversal of 21044505 is 50544012.

It is an interprime number because it is at equal distance from previous prime (21044479) and next prime (21044531).

It is not a de Polignac number, because 21044505 - 2⁵ = 21044473 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 77520 + ... + 77790.

It is an arithmetic number, because the mean of its divisors is an integer number (1096704).

Almost surely, 2^21044505 is an apocalyptic number.

It is an amenable number.

21044505 is a deficient number, since it is larger than the sum of its proper divisors (14050023).

21044505 is a wasteful number, since it uses less digits than its factorization.

21044505 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 477.

The product of its (nonzero) digits is 800, while the sum is 21.

The square root of 21044505 is about 4587.4290185244. The cubic root of 21044505 is about 276.0871784047.

Adding to 21044505 its reverse (50544012), we get a palindrome (71588517).

The spelling of 21044505 in words is "twenty-one million, forty-four thousand, five hundred five".