20840025 has 24 divisors (see below), whose sum is σ = 34774560. Its totient is φ = 11011840.

The previous prime is 20839999. The next prime is 20840033. The reversal of 20840025 is 52004802.

It is not a de Polignac number, because 20840025 - 2⁶ = 20839961 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20839983 and 20840010.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 7246 + ... + 9704.

It is an arithmetic number, because the mean of its divisors is an integer number (1448940).

Almost surely, 2^20840025 is an apocalyptic number.

20840025 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

20840025 is a deficient number, since it is larger than the sum of its proper divisors (13934535).

20840025 is a wasteful number, since it uses less digits than its factorization.

20840025 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2585 (or 2580 counting only the distinct ones).

The product of its (nonzero) digits is 640, while the sum is 21.

The square root of 20840025 is about 4565.0876223792. The cubic root of 20840025 is about 275.1900614496.

Adding to 20840025 its reverse (52004802), we get a palindrome (72844827).

The spelling of 20840025 in words is "twenty million, eight hundred forty thousand, twenty-five".