20823642 has 48 divisors (see below), whose sum is σ = 53481792. Its totient is φ = 5948640.

The previous prime is 20823619. The next prime is 20823643. The reversal of 20823642 is 24632802.

It is a super-2 number, since 2×20823642² = 867248132288328, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (20823643) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 342 + ... + 6462.

It is an arithmetic number, because the mean of its divisors is an integer number (1114204).

Almost surely, 2^20823642 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20823642, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26740896).

20823642 is an abundant number, since it is smaller than the sum of its proper divisors (32658150).

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

20823642 is an equidigital number, since it uses as much as digits as its factorization.

20823642 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6145 (or 6133 counting only the distinct ones).

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

The square root of 20823642 is about 4563.2928900083. The cubic root of 20823642 is about 275.1179306867.

The spelling of 20823642 in words is "twenty million, eight hundred twenty-three thousand, six hundred forty-two".