20002540 has 24 divisors (see below), whose sum is σ = 44476992. Its totient is φ = 7530240.

The previous prime is 20002537. The next prime is 20002553. The reversal of 20002540 is 4520002.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 20002540.

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 7 ways as a sum of consecutive naturals, for example, 29076 + ... + 29755.

It is an arithmetic number, because the mean of its divisors is an integer number (1853208).

Almost surely, 2^20002540 is an apocalyptic number.

20002540 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20002540 is an abundant number, since it is smaller than the sum of its proper divisors (24474452).

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

20002540 is a wasteful number, since it uses less digits than its factorization.

20002540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 58857 (or 58855 counting only the distinct ones).

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

The square root of 20002540 is about 4472.4199266169. The cubic root of 20002540 is about 271.4532522076.

Adding to 20002540 its reverse (4520002), we get a palindrome (24522542).

The spelling of 20002540 in words is "twenty million, two thousand, five hundred forty".