645296557 has 8 divisors (see below), whose sum is σ = 689303736. Its totient is φ = 601961472.

The previous prime is 645296551. The next prime is 645296609. The reversal of 645296557 is 755692546.

It can be written as a sum of positive squares in 4 ways, for example, as 183304521 + 461992036 = 13539^2 + 21494^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 645296557 - 2¹⁵ = 645263789 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 645296557.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645296551) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 166038 + ... + 169879.

It is an arithmetic number, because the mean of its divisors is an integer number (86162967).

Almost surely, 2^645296557 is an apocalyptic number.

It is an amenable number.

645296557 is a deficient number, since it is larger than the sum of its proper divisors (44007179).

645296557 is a wasteful number, since it uses less digits than its factorization.

645296557 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 336047.

The product of its digits is 2268000, while the sum is 49.

The square root of 645296557 is about 25402.6879876914. The cubic root of 645296557 is about 864.1446575098.

The spelling of 645296557 in words is "six hundred forty-five million, two hundred ninety-six thousand, five hundred fifty-seven".