21535044 has 12 divisors (see below), whose sum is σ = 50248464. Its totient is φ = 7178344.

The previous prime is 21535027. The next prime is 21535091. The reversal of 21535044 is 44053512.

It is a tau number, because it is divible by the number of its divisors (12).

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 897282 + ... + 897305.

It is an arithmetic number, because the mean of its divisors is an integer number (4187372).

Almost surely, 2^21535044 is an apocalyptic number.

It is an amenable number.

21535044 is an abundant number, since it is smaller than the sum of its proper divisors (28713420).

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

21535044 is a wasteful number, since it uses less digits than its factorization.

21535044 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1794594 (or 1794592 counting only the distinct ones).

The product of its (nonzero) digits is 2400, while the sum is 24.

The square root of 21535044 is about 4640.5866008512. The cubic root of 21535044 is about 278.2158839287.

Adding to 21535044 its reverse (44053512), we get a palindrome (65588556).

The spelling of 21535044 in words is "twenty-one million, five hundred thirty-five thousand, forty-four".