645857497 has 2 divisors, whose sum is σ = 645857498. Its totient is φ = 645857496.

The previous prime is 645857473. The next prime is 645857507. The reversal of 645857497 is 794758546.

645857497 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 415303641 + 230553856 = 20379^2 + 15184^2 .

It is a cyclic number.

It is not a de Polignac number, because 645857497 - 2⁷ = 645857369 is a prime.

It is a super-2 number, since 2×645857497² = 834263812862210018, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (645852497) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322928748 + 322928749.

It is an arithmetic number, because the mean of its divisors is an integer number (322928749).

Almost surely, 2^645857497 is an apocalyptic number.

It is an amenable number.

645857497 is a deficient number, since it is larger than the sum of its proper divisors (1).

645857497 is an equidigital number, since it uses as much as digits as its factorization.

645857497 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 8467200, while the sum is 55.

The square root of 645857497 is about 25413.7265468880. The cubic root of 645857497 is about 864.3949780336.

The spelling of 645857497 in words is "six hundred forty-five million, eight hundred fifty-seven thousand, four hundred ninety-seven".