20605240 has 32 divisors (see below), whose sum is σ = 48379680. Its totient is φ = 7883392.

The previous prime is 20605229. The next prime is 20605267. The reversal of 20605240 is 4250602.

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, 10279 + ... + 12118.

It is an arithmetic number, because the mean of its divisors is an integer number (1511865).

Almost surely, 2^20605240 is an apocalyptic number.

20605240 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20605240 is an abundant number, since it is smaller than the sum of its proper divisors (27774440).

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

20605240 is a wasteful number, since it uses less digits than its factorization.

20605240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22431 (or 22427 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 19.

The square root of 20605240 is about 4539.2995054303. The cubic root of 20605240 is about 274.1527200197.

Adding to 20605240 its reverse (4250602), we get a palindrome (24855842).

The spelling of 20605240 in words is "twenty million, six hundred five thousand, two hundred forty".