20423120440 has 32 divisors (see below), whose sum is σ = 46169822160. Its totient is φ = 8130528000.

The previous prime is 20423120423. The next prime is 20423120477. The reversal of 20423120440 is 4402132402.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1201461 + ... + 1218340.

Almost surely, 2^20423120440 is an apocalyptic number.

20423120440 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20423120440 is an abundant number, since it is smaller than the sum of its proper divisors (25746701720).

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

20423120440 is a wasteful number, since it uses less digits than its factorization.

20423120440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2420023 (or 2420019 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 22.

Adding to 20423120440 its reverse (4402132402), we get a palindrome (24825252842).

The spelling of 20423120440 in words is "twenty billion, four hundred twenty-three million, one hundred twenty thousand, four hundred forty".