20506425 has 24 divisors (see below), whose sum is σ = 34343040. Its totient is φ = 10795200.

The previous prime is 20506417. The next prime is 20506427. The reversal of 20506425 is 52460502.

It is not a de Polignac number, because 20506425 - 2³ = 20506417 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20506395 and 20506404.

It is not an unprimeable number, because it can be changed into a prime (20506427) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 4195 + ... + 7655.

It is an arithmetic number, because the mean of its divisors is an integer number (1430960).

Almost surely, 2^20506425 is an apocalyptic number.

20506425 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

20506425 is a deficient number, since it is larger than the sum of its proper divisors (13836615).

20506425 is a wasteful number, since it uses less digits than its factorization.

20506425 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3553 (or 3548 counting only the distinct ones).

The product of its (nonzero) digits is 2400, while the sum is 24.

The square root of 20506425 is about 4528.4020360388. The cubic root of 20506425 is about 273.7137730673.

Adding to 20506425 its reverse (52460502), we get a palindrome (72966927).

The spelling of 20506425 in words is "twenty million, five hundred six thousand, four hundred twenty-five".