20423340 has 120 divisors (see below), whose sum is σ = 73262112. Its totient is φ = 4665600.

The previous prime is 20423329. The next prime is 20423353. The reversal of 20423340 is 4332402.

It is a super-2 number, since 2×20423340² = 834225633511200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (18).

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 39 ways as a sum of consecutive naturals, for example, 10440 + ... + 12240.

Almost surely, 2^20423340 is an apocalyptic number.

20423340 is a gapful number since it is divisible by the number (20) 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 20423340, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36631056).

20423340 is an abundant number, since it is smaller than the sum of its proper divisors (52838772).

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

20423340 is a wasteful number, since it uses less digits than its factorization.

20423340 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1829 (or 1818 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 18.

The square root of 20423340 is about 4519.2189590680. The cubic root of 20423340 is about 273.3436079157.

Adding to 20423340 its reverse (4332402), we get a palindrome (24755742).

The spelling of 20423340 in words is "twenty million, four hundred twenty-three thousand, three hundred forty".