20501240 has 16 divisors (see below), whose sum is σ = 46127880. Its totient is φ = 8200480.

The previous prime is 20501237. The next prime is 20501267. The reversal of 20501240 is 4210502.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 256226 + ... + 256305.

Almost surely, 2^20501240 is an apocalyptic number.

20501240 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20501240 is an abundant number, since it is smaller than the sum of its proper divisors (25626640).

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

20501240 is a wasteful number, since it uses less digits than its factorization.

20501240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 512542 (or 512538 counting only the distinct ones).

The product of its (nonzero) digits is 80, while the sum is 14.

The square root of 20501240 is about 4527.8295020904. The cubic root of 20501240 is about 273.6907018340.

Adding to 20501240 its reverse (4210502), we get a palindrome (24711742).

The spelling of 20501240 in words is "twenty million, five hundred one thousand, two hundred forty".