20425985 has 8 divisors (see below), whose sum is σ = 24544296. Its totient is φ = 16318720.

The previous prime is 20425981. The next prime is 20425987. The reversal of 20425985 is 58952402.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 4624 + 20421361 = 68^2 + 4519^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 20425985 - 2² = 20425981 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20425981) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2087 + ... + 6723.

It is an arithmetic number, because the mean of its divisors is an integer number (3068037).

Almost surely, 2^20425985 is an apocalyptic number.

It is an amenable number.

20425985 is a deficient number, since it is larger than the sum of its proper divisors (4118311).

20425985 is an equidigital number, since it uses as much as digits as its factorization.

20425985 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5523.

The product of its (nonzero) digits is 28800, while the sum is 35.

The square root of 20425985 is about 4519.5115886565. The cubic root of 20425985 is about 273.3554075305.

The spelling of 20425985 in words is "twenty million, four hundred twenty-five thousand, nine hundred eighty-five".