21403316 has 24 divisors (see below), whose sum is σ = 41968416. Its totient is φ = 9465120.

The previous prime is 21403313. The next prime is 21403337. The reversal of 21403316 is 61330412.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21403313) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4946 + ... + 8201.

It is an arithmetic number, because the mean of its divisors is an integer number (1748684).

Almost surely, 2^21403316 is an apocalyptic number.

It is an amenable number.

21403316 is a deficient number, since it is larger than the sum of its proper divisors (20565100).

21403316 is a wasteful number, since it uses less digits than its factorization.

21403316 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13199 (or 13197 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 20.

The square root of 21403316 is about 4626.3717965594. The cubic root of 21403316 is about 277.6474491668.

Adding to 21403316 its reverse (61330412), we get a palindrome (82733728).

The spelling of 21403316 in words is "twenty-one million, four hundred three thousand, three hundred sixteen".