645876697 has 4 divisors (see below), whose sum is σ = 648937936. Its totient is φ = 642815460.

The previous prime is 645876691. The next prime is 645876703. The reversal of 645876697 is 796678546.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is an interprime number because it is at equal distance from previous prime (645876691) and next prime (645876703).

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-645876697 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (645876691) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1530303 + ... + 1530724.

It is an arithmetic number, because the mean of its divisors is an integer number (162234484).

Almost surely, 2^645876697 is an apocalyptic number.

It is an amenable number.

645876697 is a deficient number, since it is larger than the sum of its proper divisors (3061239).

645876697 is a wasteful number, since it uses less digits than its factorization.

645876697 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3061238.

The product of its digits is 15240960, while the sum is 58.

The square root of 645876697 is about 25414.1042926954. The cubic root of 645876697 is about 864.4035435037.

The spelling of 645876697 in words is "six hundred forty-five million, eight hundred seventy-six thousand, six hundred ninety-seven".