21041736 has 32 divisors (see below), whose sum is σ = 53200800. Its totient is φ = 6934400.

The previous prime is 21041731. The next prime is 21041737. The reversal of 21041736 is 63714012.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is not an unprimeable number, because it can be changed into a prime (21041731) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2790 + ... + 7061.

It is an arithmetic number, because the mean of its divisors is an integer number (1662525).

Almost surely, 2^21041736 is an apocalyptic number.

It is an amenable number.

21041736 is an abundant number, since it is smaller than the sum of its proper divisors (32159064).

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

21041736 is a wasteful number, since it uses less digits than its factorization.

21041736 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9949 (or 9945 counting only the distinct ones).

The product of its (nonzero) digits is 1008, while the sum is 24.

The square root of 21041736 is about 4587.1272055612. The cubic root of 21041736 is about 276.0750688472.

Adding to 21041736 its reverse (63714012), we get a palindrome (84755748).

The spelling of 21041736 in words is "twenty-one million, forty-one thousand, seven hundred thirty-six".