20425861 has 4 divisors (see below), whose sum is σ = 20436300. Its totient is φ = 20415424.

The previous prime is 20425849. The next prime is 20425879. The reversal of 20425861 is 16852402.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 5909761 + 14516100 = 2431^2 + 3810^2 .

It is a cyclic number.

It is not a de Polignac number, because 20425861 - 2¹¹ = 20423813 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20420861) 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 3 ways as a sum of consecutive naturals, for example, 1306 + ... + 6523.

It is an arithmetic number, because the mean of its divisors is an integer number (5109075).

Almost surely, 2^20425861 is an apocalyptic number.

It is an amenable number.

20425861 is a deficient number, since it is larger than the sum of its proper divisors (10439).

20425861 is an equidigital number, since it uses as much as digits as its factorization.

20425861 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10438.

The product of its (nonzero) digits is 3840, while the sum is 28.

The square root of 20425861 is about 4519.4978703391. The cubic root of 20425861 is about 273.3548543766.

The spelling of 20425861 in words is "twenty million, four hundred twenty-five thousand, eight hundred sixty-one".