1625682661 has 2 divisors, whose sum is σ = 1625682662. Its totient is φ = 1625682660.

The previous prime is 1625682631. The next prime is 1625682683. The reversal of 1625682661 is 1662865261.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 942121636 + 683561025 = 30694^2 + 26145^2 .

It is an emirp because it is prime and its reverse (1662865261) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1625682661 - 2⁵ = 1625682629 is a prime.

It is a super-2 number, since 2×1625682661² = 5285688228552081842, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1625682601) 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, 812841330 + 812841331.

It is an arithmetic number, because the mean of its divisors is an integer number (812841331).

Almost surely, 2^1625682661 is an apocalyptic number.

It is an amenable number.

1625682661 is a deficient number, since it is larger than the sum of its proper divisors (1).

1625682661 is an equidigital number, since it uses as much as digits as its factorization.

1625682661 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 207360, while the sum is 43.

The square root of 1625682661 is about 40319.7552199911. The cubic root of 1625682661 is about 1175.8319530671.

The spelling of 1625682661 in words is "one billion, six hundred twenty-five million, six hundred eighty-two thousand, six hundred sixty-one".