21838716 has 36 divisors (see below), whose sum is σ = 55528200. Its totient is φ = 7236768.

The previous prime is 21838679. The next prime is 21838723. The reversal of 21838716 is 61783812.

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4750 + ... + 8138.

It is an arithmetic number, because the mean of its divisors is an integer number (1542450).

Almost surely, 2^21838716 is an apocalyptic number.

It is an amenable number.

21838716 is an abundant number, since it is smaller than the sum of its proper divisors (33689484).

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

21838716 is a wasteful number, since it uses less digits than its factorization.

21838716 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3578 (or 3573 counting only the distinct ones).

The product of its digits is 16128, while the sum is 36.

The square root of 21838716 is about 4673.1912008819. The cubic root of 21838716 is about 279.5175194338.

The spelling of 21838716 in words is "twenty-one million, eight hundred thirty-eight thousand, seven hundred sixteen".