645161537 has 2 divisors, whose sum is σ = 645161538. Its totient is φ = 645161536.

The previous prime is 645161497. The next prime is 645161567. The reversal of 645161537 is 735161546.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 607326736 + 37834801 = 24644^2 + 6151^2 .

It is a cyclic number.

It is not a de Polignac number, because 645161537 - 2¹⁰ = 645160513 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 645161537.

It is not a weakly prime, because it can be changed into another prime (645161567) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322580768 + 322580769.

It is an arithmetic number, because the mean of its divisors is an integer number (322580769).

Almost surely, 2^645161537 is an apocalyptic number.

It is an amenable number.

645161537 is a deficient number, since it is larger than the sum of its proper divisors (1).

645161537 is an equidigital number, since it uses as much as digits as its factorization.

645161537 is an evil number, because the sum of its binary digits is even.

The product of its digits is 75600, while the sum is 38.

The square root of 645161537 is about 25400.0302558875. The cubic root of 645161537 is about 864.0843829228.

Subtracting 645161537 from its reverse (735161546), we obtain a palindrome (90000009).

The spelling of 645161537 in words is "six hundred forty-five million, one hundred sixty-one thousand, five hundred thirty-seven".