20507440 has 60 divisors (see below), whose sum is σ = 50706576. Its totient is φ = 7711744.

The previous prime is 20507429. The next prime is 20507471. The reversal of 20507440 is 4470502.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 22677 + ... + 23563.

Almost surely, 2^20507440 is an apocalyptic number.

20507440 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 20507440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25353288).

20507440 is an abundant number, since it is smaller than the sum of its proper divisors (30199136).

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

20507440 is a wasteful number, since it uses less digits than its factorization.

20507440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 934 (or 911 counting only the distinct ones).

The product of its (nonzero) digits is 1120, while the sum is 22.

The square root of 20507440 is about 4528.5141050901. The cubic root of 20507440 is about 273.7182889673.

Adding to 20507440 its reverse (4470502), we get a palindrome (24977942).

The spelling of 20507440 in words is "twenty million, five hundred seven thousand, four hundred forty".