21040632 has 24 divisors (see below), whose sum is σ = 56985240. Its totient is φ = 7013520.

The previous prime is 21040627. The next prime is 21040633. The reversal of 21040632 is 23604012.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (24).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21040633) by changing a digit.

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 5 ways as a sum of consecutive naturals, for example, 146044 + ... + 146187.

It is an arithmetic number, because the mean of its divisors is an integer number (2374385).

Almost surely, 2^21040632 is an apocalyptic number.

It is an amenable number.

21040632 is an abundant number, since it is smaller than the sum of its proper divisors (35944608).

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

21040632 is a wasteful number, since it uses less digits than its factorization.

21040632 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 292243 (or 292236 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 18.

The square root of 21040632 is about 4587.0068672283. The cubic root of 21040632 is about 276.0702404718.

Adding to 21040632 its reverse (23604012), we get a palindrome (44644644).

The spelling of 21040632 in words is "twenty-one million, forty thousand, six hundred thirty-two".