20643084 has 108 divisors (see below), whose sum is σ = 65646672. Its totient is φ = 5353920.

The previous prime is 20643061. The next prime is 20643107. The reversal of 20643084 is 48034602.

It is an interprime number because it is at equal distance from previous prime (20643061) and next prime (20643107).

It is a super-2 number, since 2×20643084² = 852273834062112, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 30154 + ... + 30830.

Almost surely, 2^20643084 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20643084, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32823336).

20643084 is an abundant number, since it is smaller than the sum of its proper divisors (45003588).

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

20643084 is a wasteful number, since it uses less digits than its factorization.

20643084 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 716 (or 700 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 27.

The square root of 20643084 is about 4543.4660777869. The cubic root of 20643084 is about 274.3204555139.

Adding to 20643084 its reverse (48034602), we get a palindrome (68677686).

The spelling of 20643084 in words is "twenty million, six hundred forty-three thousand, eighty-four".