21571044 has 24 divisors (see below), whose sum is σ = 54908448. Its totient is φ = 6536640.

The previous prime is 21571001. The next prime is 21571051. The reversal of 21571044 is 44017512.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 81577 + ... + 81840.

It is an arithmetic number, because the mean of its divisors is an integer number (2287852).

Almost surely, 2^21571044 is an apocalyptic number.

It is an amenable number.

21571044 is an abundant number, since it is smaller than the sum of its proper divisors (33337404).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21571044 is a wasteful number, since it uses less digits than its factorization.

21571044 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 163435 (or 163433 counting only the distinct ones).

The product of its (nonzero) digits is 1120, while the sum is 24.

The square root of 21571044 is about 4644.4638011293. The cubic root of 21571044 is about 278.3708282124.

Adding to 21571044 its reverse (44017512), we get a palindrome (65588556).

The spelling of 21571044 in words is "twenty-one million, five hundred seventy-one thousand, forty-four".