20004640 has 24 divisors (see below), whose sum is σ = 47261340. Its totient is φ = 8001792.

The previous prime is 20004583. The next prime is 20004667. The reversal of 20004640 is 4640002.

It can be written as a sum of positive squares in 2 ways, for example, as 19963024 + 41616 = 4468^2 + 204^2 .

It is a Harshad number since it is a multiple of its sum of digits (16).

It is an unprimeable number.

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, 62355 + ... + 62674.

Almost surely, 2^20004640 is an apocalyptic number.

20004640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20004640 is an abundant number, since it is smaller than the sum of its proper divisors (27256700).

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

20004640 is a wasteful number, since it uses less digits than its factorization.

20004640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 125044 (or 125036 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 16.

The square root of 20004640 is about 4472.6546926853. The cubic root of 20004640 is about 271.4627515326.

Adding to 20004640 its reverse (4640002), we get a palindrome (24644642).

The spelling of 20004640 in words is "twenty million, four thousand, six hundred forty".