645427537 has 2 divisors, whose sum is σ = 645427538. Its totient is φ = 645427536.

The previous prime is 645427507. The next prime is 645427543. The reversal of 645427537 is 735724546.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 588741696 + 56685841 = 24264^2 + 7529^2 .

It is a cyclic number.

It is not a de Polignac number, because 645427537 - 2¹¹ = 645425489 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 645427493 and 645427502.

It is not a weakly prime, because it can be changed into another prime (645427507) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322713768 + 322713769.

It is an arithmetic number, because the mean of its divisors is an integer number (322713769).

Almost surely, 2^645427537 is an apocalyptic number.

It is an amenable number.

645427537 is a deficient number, since it is larger than the sum of its proper divisors (1).

645427537 is an equidigital number, since it uses as much as digits as its factorization.

645427537 is an evil number, because the sum of its binary digits is even.

The product of its digits is 705600, while the sum is 43.

The square root of 645427537 is about 25405.2659305113. The cubic root of 645427537 is about 864.2031205575.

The spelling of 645427537 in words is "six hundred forty-five million, four hundred twenty-seven thousand, five hundred thirty-seven".