20023440 has 40 divisors (see below), whose sum is σ = 62073408. Its totient is φ = 5339520.

The previous prime is 20023429. The next prime is 20023441. The reversal of 20023440 is 4432002.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (40).

It is a Harshad number since it is a multiple of its sum of digits (15).

It is not an unprimeable number, because it can be changed into a prime (20023441) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 41476 + ... + 41955.

Almost surely, 2^20023440 is an apocalyptic number.

20023440 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20023440 is an abundant number, since it is smaller than the sum of its proper divisors (42049968).

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

20023440 is a wasteful number, since it uses less digits than its factorization.

20023440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 83447 (or 83441 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 15.

The square root of 20023440 is about 4474.7558592620. The cubic root of 20023440 is about 271.5477635071.

Adding to 20023440 its reverse (4432002), we get a palindrome (24455442).

The spelling of 20023440 in words is "twenty million, twenty-three thousand, four hundred forty".