20312784 has 30 divisors (see below), whose sum is σ = 56847986. Its totient is φ = 6770880.

The previous prime is 20312783. The next prime is 20312791. The reversal of 20312784 is 48721302.

It can be written as a sum of positive squares in only one way, i.e., 19607184 + 705600 = 4428^2 + 840^2 .

It is a Smith number, since the sum of its digits (27) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20312783) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 70387 + ... + 70674.

Almost surely, 2^20312784 is an apocalyptic number.

20312784 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

20312784 is an abundant number, since it is smaller than the sum of its proper divisors (36535202).

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

20312784 is a wasteful number, since it uses less digits than its factorization.

20312784 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 141075 (or 141066 counting only the distinct ones).

The product of its (nonzero) digits is 2688, while the sum is 27.

The square root of 20312784 is about 4506.9706011910. The cubic root of 20312784 is about 272.8494923720.

The spelling of 20312784 in words is "twenty million, three hundred twelve thousand, seven hundred eighty-four".