20726784 has 132 divisors (see below), whose sum is σ = 64824396. Its totient is φ = 6340608.

The previous prime is 20726779. The next prime is 20726789. The reversal of 20726784 is 48762702.

It is an interprime number because it is at equal distance from previous prime (20726779) and next prime (20726789).

It can be written as a sum of positive squares in 2 ways, for example, as 11289600 + 9437184 = 3360^2 + 3072^2 .

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20726789) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 119722 + ... + 119894.

Almost surely, 2^20726784 is an apocalyptic number.

20726784 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 20726784, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32412198).

20726784 is an abundant number, since it is smaller than the sum of its proper divisors (44097612).

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

20726784 is a wasteful number, since it uses less digits than its factorization.

20726784 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 212 (or 191 counting only the distinct ones).

The product of its (nonzero) digits is 37632, while the sum is 36.

The square root of 20726784 is about 4552.6677893297. The cubic root of 20726784 is about 274.6907112307.

The spelling of 20726784 in words is "twenty million, seven hundred twenty-six thousand, seven hundred eighty-four".