1665725051 has 2 divisors, whose sum is σ = 1665725052. Its totient is φ = 1665725050.

The previous prime is 1665724909. The next prime is 1665725053. The reversal of 1665725051 is 1505275661.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1665725051 - 2²² = 1661530747 is a prime.

Together with 1665725053, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 1665724996 and 1665725014.

It is not a weakly prime, because it can be changed into another prime (1665725053) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 832862525 + 832862526.

It is an arithmetic number, because the mean of its divisors is an integer number (832862526).

Almost surely, 2^1665725051 is an apocalyptic number.

1665725051 is a deficient number, since it is larger than the sum of its proper divisors (1).

1665725051 is an equidigital number, since it uses as much as digits as its factorization.

1665725051 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 63000, while the sum is 38.

The square root of 1665725051 is about 40813.2950274785. The cubic root of 1665725051 is about 1185.4077776704.

The spelling of 1665725051 in words is "one billion, six hundred sixty-five million, seven hundred twenty-five thousand, fifty-one".