21416740 has 24 divisors (see below), whose sum is σ = 45594360. Its totient is φ = 8448768.

The previous prime is 21416737. The next prime is 21416779. The reversal of 21416740 is 4761412.

It can be written as a sum of positive squares in 4 ways, for example, as 3709476 + 17707264 = 1926^2 + 4208^2 .

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5875 + ... + 8794.

It is an arithmetic number, because the mean of its divisors is an integer number (1899765).

Almost surely, 2^21416740 is an apocalyptic number.

21416740 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21416740 is an abundant number, since it is smaller than the sum of its proper divisors (24177620).

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

21416740 is a wasteful number, since it uses less digits than its factorization.

21416740 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14751 (or 14749 counting only the distinct ones).

The product of its (nonzero) digits is 1344, while the sum is 25.

The square root of 21416740 is about 4627.8223820713. The cubic root of 21416740 is about 277.7054831714.

The spelling of 21416740 in words is "twenty-one million, four hundred sixteen thousand, seven hundred forty".