21053982 has 8 divisors (see below), whose sum is σ = 42107976. Its totient is φ = 7017992.

The previous prime is 21053969. The next prime is 21053983. The reversal of 21053982 is 28935012.

It is a happy number.

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

21053982 is an admirable number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21053983) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1754493 + ... + 1754504.

It is an arithmetic number, because the mean of its divisors is an integer number (5263497).

Almost surely, 2^21053982 is an apocalyptic number.

21053982 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

21053982 is a wasteful number, since it uses less digits than its factorization.

21053982 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3509002.

The product of its (nonzero) digits is 4320, while the sum is 30.

The square root of 21053982 is about 4588.4618337739. The cubic root of 21053982 is about 276.1286157542.

Adding to 21053982 its reverse (28935012), we get a palindrome (49988994).

The spelling of 21053982 in words is "twenty-one million, fifty-three thousand, nine hundred eighty-two".