645909527 has 2 divisors, whose sum is σ = 645909528. Its totient is φ = 645909526.

The previous prime is 645909499. The next prime is 645909557. The reversal of 645909527 is 725909546.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-645909527 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (645909557) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322954763 + 322954764.

It is an arithmetic number, because the mean of its divisors is an integer number (322954764).

Almost surely, 2^645909527 is an apocalyptic number.

645909527 is a deficient number, since it is larger than the sum of its proper divisors (1).

645909527 is an equidigital number, since it uses as much as digits as its factorization.

645909527 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 680400, while the sum is 47.

The square root of 645909527 is about 25414.7501856697. The cubic root of 645909527 is about 864.4181891719.

The spelling of 645909527 in words is "six hundred forty-five million, nine hundred nine thousand, five hundred twenty-seven".