645434042657 has 8 divisors (see below), whose sum is σ = 646175597352. Its totient is φ = 644692608000.

The previous prime is 645434042653. The next prime is 645434042753. The reversal of 645434042657 is 756240434546.

645434042657 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 419665569856 + 225768472801 = 647816^2 + 475151^2 .

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 645434042657 - 2² = 645434042653 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (645434042653) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 14918657 + ... + 14961857.

It is an arithmetic number, because the mean of its divisors is an integer number (80771949669).

Almost surely, 2^645434042657 is an apocalyptic number.

It is an amenable number.

645434042657 is a deficient number, since it is larger than the sum of its proper divisors (741554695).

645434042657 is a wasteful number, since it uses less digits than its factorization.

645434042657 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 60019.

The product of its (nonzero) digits is 9676800, while the sum is 50.

The spelling of 645434042657 in words is "six hundred forty-five billion, four hundred thirty-four million, forty-two thousand, six hundred fifty-seven".