645295997 has 2 divisors, whose sum is σ = 645295998. Its totient is φ = 645295996.

The previous prime is 645295991. The next prime is 645296053. The reversal of 645295997 is 799592546.

It is an a-pointer prime, because the next prime (645296053) can be obtained adding 645295997 to its sum of digits (56).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 631315876 + 13980121 = 25126^2 + 3739^2 .

It is a cyclic number.

It is not a de Polignac number, because 645295997 - 2¹² = 645291901 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (645295991) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322647998 + 322647999.

It is an arithmetic number, because the mean of its divisors is an integer number (322647999).

Almost surely, 2^645295997 is an apocalyptic number.

It is an amenable number.

645295997 is a deficient number, since it is larger than the sum of its proper divisors (1).

645295997 is an equidigital number, since it uses as much as digits as its factorization.

645295997 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6123600, while the sum is 56.

The square root of 645295997 is about 25402.6769652334. The cubic root of 645295997 is about 864.1444075363.

The spelling of 645295997 in words is "six hundred forty-five million, two hundred ninety-five thousand, nine hundred ninety-seven".