20009040 has 80 divisors (see below), whose sum is σ = 62460288. Its totient is φ = 5298688.

The previous prime is 20009029. The next prime is 20009047. The reversal of 20009040 is 4090002.

It is a tau number, because it is divible by the number of its divisors (80).

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20009047) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 62962 + ... + 63278.

Almost surely, 2^20009040 is an apocalyptic number.

20009040 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 20009040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31230144).

20009040 is an abundant number, since it is smaller than the sum of its proper divisors (42451248).

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

20009040 is a wasteful number, since it uses less digits than its factorization.

20009040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 596 (or 590 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 15.

The square root of 20009040 is about 4473.1465435418. The cubic root of 20009040 is about 271.4826527246.

Adding to 20009040 its reverse (4090002), we get a palindrome (24099042).

The spelling of 20009040 in words is "twenty million, nine thousand, forty".