21403116 has 60 divisors (see below), whose sum is σ = 63951888. Its totient is φ = 6114528.

The previous prime is 21403111. The next prime is 21403117. The reversal of 21403116 is 61130412.

It is a happy number.

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 (21403111) by changing a digit.

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 19 ways as a sum of consecutive naturals, for example, 2451 + ... + 6986.

Almost surely, 2^21403116 is an apocalyptic number.

It is an amenable number.

21403116 is an abundant number, since it is smaller than the sum of its proper divisors (42548772).

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

21403116 is a wasteful number, since it uses less digits than its factorization.

21403116 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9460 (or 9449 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

The square root of 21403116 is about 4626.3501812984. The cubic root of 21403116 is about 277.6465843528.

Adding to 21403116 its reverse (61130412), we get a palindrome (82533528).

The spelling of 21403116 in words is "twenty-one million, four hundred three thousand, one hundred sixteen".