21457716 has 48 divisors (see below), whose sum is σ = 57447936. Its totient is φ = 6106464.

The previous prime is 21457703. The next prime is 21457717. The reversal of 21457716 is 61775412.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21457717) 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 15 ways as a sum of consecutive naturals, for example, 38955 + ... + 39501.

It is an arithmetic number, because the mean of its divisors is an integer number (1196832).

Almost surely, 2^21457716 is an apocalyptic number.

It is an amenable number.

21457716 is an abundant number, since it is smaller than the sum of its proper divisors (35990220).

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

21457716 is a wasteful number, since it uses less digits than its factorization.

21457716 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1028 (or 1026 counting only the distinct ones).

The product of its digits is 11760, while the sum is 33.

The square root of 21457716 is about 4632.2474027193. The cubic root of 21457716 is about 277.8824788359.

The spelling of 21457716 in words is "twenty-one million, four hundred fifty-seven thousand, seven hundred sixteen".