21418716 has 24 divisors (see below), whose sum is σ = 54520704. Its totient is φ = 6490480.

The previous prime is 21418703. The next prime is 21418723. The reversal of 21418716 is 61781412.

It is a super-2 number, since 2×21418716² = 917522790177312, which contains 22 as substring.

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, 81000 + ... + 81263.

It is an arithmetic number, because the mean of its divisors is an integer number (2271696).

Almost surely, 2^21418716 is an apocalyptic number.

It is an amenable number.

21418716 is an abundant number, since it is smaller than the sum of its proper divisors (33101988).

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

21418716 is a wasteful number, since it uses less digits than its factorization.

21418716 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 162281 (or 162279 counting only the distinct ones).

The product of its digits is 2688, while the sum is 30.

The square root of 21418716 is about 4628.0358684868. The cubic root of 21418716 is about 277.7140236738.

The spelling of 21418716 in words is "twenty-one million, four hundred eighteen thousand, seven hundred sixteen".