1665825397 has 2 divisors, whose sum is σ = 1665825398. Its totient is φ = 1665825396.

The previous prime is 1665825383. The next prime is 1665825419. The reversal of 1665825397 is 7935285661.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1586508561 + 79316836 = 39831^2 + 8906^2 .

It is a cyclic number.

It is not a de Polignac number, because 1665825397 - 2¹¹ = 1665823349 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1665825307) 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, 832912698 + 832912699.

It is an arithmetic number, because the mean of its divisors is an integer number (832912699).

Almost surely, 2^1665825397 is an apocalyptic number.

It is an amenable number.

1665825397 is a deficient number, since it is larger than the sum of its proper divisors (1).

1665825397 is an equidigital number, since it uses as much as digits as its factorization.

1665825397 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2721600, while the sum is 52.

The square root of 1665825397 is about 40814.5243387694. The cubic root of 1665825397 is about 1185.4315808265.

The spelling of 1665825397 in words is "one billion, six hundred sixty-five million, eight hundred twenty-five thousand, three hundred ninety-seven".