20705982 has 16 divisors (see below), whose sum is σ = 45176832. Its totient is φ = 6274520.

The previous prime is 20705981. The next prime is 20706019. The reversal of 20705982 is 28950702.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20705981) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 156798 + ... + 156929.

It is an arithmetic number, because the mean of its divisors is an integer number (2823552).

Almost surely, 2^20705982 is an apocalyptic number.

20705982 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

20705982 is an abundant number, since it is smaller than the sum of its proper divisors (24470850).

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

20705982 is a wasteful number, since it uses less digits than its factorization.

20705982 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 313743.

The product of its (nonzero) digits is 10080, while the sum is 33.

The square root of 20705982 is about 4550.3826212748. The cubic root of 20705982 is about 274.5987846224.

The spelling of 20705982 in words is "twenty million, seven hundred five thousand, nine hundred eighty-two".