20115440 has 20 divisors (see below), whose sum is σ = 46768584. Its totient is φ = 8046144.

The previous prime is 20115439. The next prime is 20115449. The reversal of 20115440 is 4451102.

It is a tau number, because it is divible by the number of its divisors (20).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20115449) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 125642 + ... + 125801.

Almost surely, 2^20115440 is an apocalyptic number.

20115440 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20115440 is an abundant number, since it is smaller than the sum of its proper divisors (26653144).

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

20115440 is a wasteful number, since it uses less digits than its factorization.

20115440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 251456 (or 251450 counting only the distinct ones).

The product of its (nonzero) digits is 160, while the sum is 17.

The square root of 20115440 is about 4485.0239687208. The cubic root of 20115440 is about 271.9630140021.

Adding to 20115440 its reverse (4451102), we get a palindrome (24566542).

The spelling of 20115440 in words is "twenty million, one hundred fifteen thousand, four hundred forty".