21055982 has 8 divisors (see below), whose sum is σ = 32318616. Its totient is φ = 10283112.

The previous prime is 21055967. The next prime is 21056011. The reversal of 21055982 is 28955012.

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, 122333 + ... + 122504.

It is an arithmetic number, because the mean of its divisors is an integer number (4039827).

Almost surely, 2^21055982 is an apocalyptic number.

21055982 is a deficient number, since it is larger than the sum of its proper divisors (11262634).

21055982 is a wasteful number, since it uses less digits than its factorization.

21055982 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 244882.

The product of its (nonzero) digits is 7200, while the sum is 32.

The square root of 21055982 is about 4588.6797665560. The cubic root of 21055982 is about 276.1373589894.

The spelling of 21055982 in words is "twenty-one million, fifty-five thousand, nine hundred eighty-two".