20520040 has 16 divisors (see below), whose sum is σ = 46170180. Its totient is φ = 8208000.

The previous prime is 20520029. The next prime is 20520041. The reversal of 20520040 is 4002502.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 17757796 + 2762244 = 4214^2 + 1662^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 20520040.

It is not an unprimeable number, because it can be changed into a prime (20520041) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 256461 + ... + 256540.

Almost surely, 2^20520040 is an apocalyptic number.

20520040 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20520040 is an abundant number, since it is smaller than the sum of its proper divisors (25650140).

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

20520040 is a wasteful number, since it uses less digits than its factorization.

20520040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 513012 (or 513008 counting only the distinct ones).

The product of its (nonzero) digits is 80, while the sum is 13.

The square root of 20520040 is about 4529.9050762682. The cubic root of 20520040 is about 273.7743360140.

Adding to 20520040 its reverse (4002502), we get a palindrome (24522542).

The spelling of 20520040 in words is "twenty million, five hundred twenty thousand, forty".