21982464 has 216 divisors, whose sum is σ = 76527360. Its totient is φ = 5935104.

The previous prime is 21982451. The next prime is 21982481. The reversal of 21982464 is 46428912.

21982464 is a `hidden beast` number, since 2 + 198 + 2 + 464 = 666.

It is a super-2 number, since 2×21982464² = 966457447022592, which contains 22 as substring.

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

It is a nude number because it is divisible by every one of its digits.

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 23 ways as a sum of consecutive naturals, for example, 467689 + ... + 467735.

Almost surely, 2^21982464 is an apocalyptic number.

21982464 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21982464, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38263680).

21982464 is an abundant number, since it is smaller than the sum of its proper divisors (54544896).

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

21982464 is a wasteful number, since it uses less digits than its factorization.

21982464 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 105 (or 88 counting only the distinct ones).

The product of its digits is 27648, while the sum is 36.

The square root of 21982464 is about 4688.5460432846. The cubic root of 21982464 is about 280.1294639399.

The spelling of 21982464 in words is "twenty-one million, nine hundred eighty-two thousand, four hundred sixty-four".