21032916 has 24 divisors (see below), whose sum is σ = 49514304. Its totient is φ = 6948480.

The previous prime is 21032903. The next prime is 21032933. The reversal of 21032916 is 61923012.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6400 + ... + 9111.

It is an arithmetic number, because the mean of its divisors is an integer number (2063096).

Almost surely, 2^21032916 is an apocalyptic number.

It is an amenable number.

21032916 is an abundant number, since it is smaller than the sum of its proper divisors (28481388).

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

21032916 is a wasteful number, since it uses less digits than its factorization.

21032916 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15631 (or 15629 counting only the distinct ones).

The product of its (nonzero) digits is 648, while the sum is 24.

The square root of 21032916 is about 4586.1657187677. The cubic root of 21032916 is about 276.0364896095.

Adding to 21032916 its reverse (61923012), we get a palindrome (82955928).

The spelling of 21032916 in words is "twenty-one million, thirty-two thousand, nine hundred sixteen".