21649382 has 8 divisors (see below), whose sum is σ = 33229416. Its totient is φ = 10572912.

The previous prime is 21649361. The next prime is 21649429. The reversal of 21649382 is 28394612.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 125783 + ... + 125954.

It is an arithmetic number, because the mean of its divisors is an integer number (4153677).

Almost surely, 2^21649382 is an apocalyptic number.

21649382 is a deficient number, since it is larger than the sum of its proper divisors (11580034).

21649382 is a wasteful number, since it uses less digits than its factorization.

21649382 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 251782.

The product of its digits is 20736, while the sum is 35.

The square root of 21649382 is about 4652.8896397830. The cubic root of 21649382 is about 278.7074008381.

The spelling of 21649382 in words is "twenty-one million, six hundred forty-nine thousand, three hundred eighty-two".