21456316 has 18 divisors (see below), whose sum is σ = 43679328. Its totient is φ = 9195480.

The previous prime is 21456313. The next prime is 21456319. The reversal of 21456316 is 61365412.

It is an interprime number because it is at equal distance from previous prime (21456313) and next prime (21456319).

It is a Harshad number since it is a multiple of its sum of digits (28).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21456311) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 54540 + ... + 54931.

Almost surely, 2^21456316 is an apocalyptic number.

It is an amenable number.

21456316 is an abundant number, since it is smaller than the sum of its proper divisors (22223012).

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

21456316 is a wasteful number, since it uses less digits than its factorization.

21456316 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 109489 (or 109480 counting only the distinct ones).

The product of its digits is 4320, while the sum is 28.

The square root of 21456316 is about 4632.0962857005. The cubic root of 21456316 is about 277.8764352612.

The spelling of 21456316 in words is "twenty-one million, four hundred fifty-six thousand, three hundred sixteen".