21055416 has 32 divisors (see below), whose sum is σ = 53634960. Its totient is φ = 6885632.

The previous prime is 21055409. The next prime is 21055429. The reversal of 21055416 is 61455012.

It is a Harshad number since it is a multiple of its sum of digits (24).

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, 7005 + ... + 9548.

Almost surely, 2^21055416 is an apocalyptic number.

It is an amenable number.

21055416 is an abundant number, since it is smaller than the sum of its proper divisors (32579544).

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

21055416 is a wasteful number, since it uses less digits than its factorization.

21055416 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16615 (or 16611 counting only the distinct ones).

The product of its (nonzero) digits is 1200, while the sum is 24.

The square root of 21055416 is about 4588.6180926288. The cubic root of 21055416 is about 276.1348847100.

The spelling of 21055416 in words is "twenty-one million, fifty-five thousand, four hundred sixteen".