20520340 has 24 divisors (see below), whose sum is σ = 43492680. Its totient is φ = 8131968.

The previous prime is 20520337. The next prime is 20520389. The reversal of 20520340 is 4302502.

It can be written as a sum of positive squares in 4 ways, for example, as 10458756 + 10061584 = 3234^2 + 3172^2 .

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, 2527 + ... + 6886.

It is an arithmetic number, because the mean of its divisors is an integer number (1812195).

Almost surely, 2^20520340 is an apocalyptic number.

20520340 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20520340 is an abundant number, since it is smaller than the sum of its proper divisors (22972340).

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

20520340 is a wasteful number, since it uses less digits than its factorization.

20520340 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9531 (or 9529 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 16.

The square root of 20520340 is about 4529.9381894238. The cubic root of 20520340 is about 273.7756701879.

Adding to 20520340 its reverse (4302502), we get a palindrome (24822842).

The spelling of 20520340 in words is "twenty million, five hundred twenty thousand, three hundred forty".