20763864 has 96 divisors (see below), whose sum is σ = 63685440. Its totient is φ = 6285600.

The previous prime is 20763839. The next prime is 20763881. The reversal of 20763864 is 46836702.

It is a super-2 number, since 2×20763864² = 862276096420992, which contains 22 as substring.

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

It is a congruent number.

It is an unprimeable number.

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 23 ways as a sum of consecutive naturals, for example, 20899 + ... + 21869.

It is an arithmetic number, because the mean of its divisors is an integer number (663390).

Almost surely, 2^20763864 is an apocalyptic number.

20763864 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 20763864, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31842720).

20763864 is an abundant number, since it is smaller than the sum of its proper divisors (42921576).

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

20763864 is a wasteful number, since it uses less digits than its factorization.

20763864 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1003 (or 987 counting only the distinct ones).

The product of its (nonzero) digits is 48384, while the sum is 36.

The square root of 20763864 is about 4556.7383071667. The cubic root of 20763864 is about 274.8544199158.

It can be divided in two parts, 207638 and 64, that added together give a palindrome (207702).

The spelling of 20763864 in words is "twenty million, seven hundred sixty-three thousand, eight hundred sixty-four".