21040964 has 12 divisors (see below), whose sum is σ = 42081984. Its totient is φ = 9017544.

The previous prime is 21040963. The next prime is 21040967. The reversal of 21040964 is 46904012.

21040964 is an admirable number.

It is not an unprimeable number, because it can be changed into a prime (21040963) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 375704 + ... + 375759.

It is an arithmetic number, because the mean of its divisors is an integer number (3506832).

Almost surely, 2^21040964 is an apocalyptic number.

It is an amenable number.

21040964 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

21040964 is a wasteful number, since it uses less digits than its factorization.

21040964 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 751474 (or 751472 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 26.

The square root of 21040964 is about 4587.0430562618. The cubic root of 21040964 is about 276.0716925010.

Adding to 21040964 its reverse (46904012), we get a palindrome (67944976).

The spelling of 21040964 in words is "twenty-one million, forty thousand, nine hundred sixty-four".