20125665 has 80 divisors (see below), whose sum is σ = 42746880. Its totient is φ = 8864640.

The previous prime is 20125649. The next prime is 20125697. The reversal of 20125665 is 56652102.

It is not a de Polignac number, because 20125665 - 2⁴ = 20125649 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an unprimeable number.

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 79 ways as a sum of consecutive naturals, for example, 87771 + ... + 87999.

It is an arithmetic number, because the mean of its divisors is an integer number (534336).

Almost surely, 2^20125665 is an apocalyptic number.

It is an amenable number.

20125665 is an abundant number, since it is smaller than the sum of its proper divisors (22621215).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20125665 is a wasteful number, since it uses less digits than its factorization.

20125665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 284 (or 275 counting only the distinct ones).

The product of its (nonzero) digits is 3600, while the sum is 27.

The square root of 20125665 is about 4486.1637286216. The cubic root of 20125665 is about 272.0090872469.

Adding to 20125665 its reverse (56652102), we get a palindrome (76777767).

The spelling of 20125665 in words is "twenty million, one hundred twenty-five thousand, six hundred sixty-five".