20405025 has 36 divisors (see below), whose sum is σ = 38146368. Its totient is φ = 10406880.

The previous prime is 20404999. The next prime is 20405027. The reversal of 20405025 is 52050402.

It is not a de Polignac number, because 20405025 - 2⁶ = 20404961 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20404989 and 20405007.

It is not an unprimeable number, because it can be changed into a prime (20405027) by changing a digit.

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 35 ways as a sum of consecutive naturals, for example, 3204 + ... + 7146.

Almost surely, 2^20405025 is an apocalyptic number.

20405025 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

20405025 is a deficient number, since it is larger than the sum of its proper divisors (17741343).

20405025 is a wasteful number, since it uses less digits than its factorization.

20405025 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3982 (or 3974 counting only the distinct ones).

The product of its (nonzero) digits is 400, while the sum is 18.

The square root of 20405025 is about 4517.1921588527. The cubic root of 20405025 is about 273.2618748688.

Adding to 20405025 its reverse (52050402), we get a palindrome (72455427).

The spelling of 20405025 in words is "twenty million, four hundred five thousand, twenty-five".