641896532785 has 4 divisors (see below), whose sum is σ = 770275839348. Its totient is φ = 513517226224.

The previous prime is 641896532759. The next prime is 641896532791. The reversal of 641896532785 is 587235698146.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 258829615009 + 383066917776 = 508753^2 + 618924^2 .

It is a cyclic number.

It is not a de Polignac number, because 641896532785 - 2⁹ = 641896532273 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 64189653274 + ... + 64189653283.

It is an arithmetic number, because the mean of its divisors is an integer number (192568959837).

Almost surely, 2^641896532785 is an apocalyptic number.

It is an amenable number.

641896532785 is a deficient number, since it is larger than the sum of its proper divisors (128379306563).

641896532785 is a wasteful number, since it uses less digits than its factorization.

641896532785 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 128379306562.

The product of its digits is 87091200, while the sum is 64.

The spelling of 641896532785 in words is "six hundred forty-one billion, eight hundred ninety-six million, five hundred thirty-two thousand, seven hundred eighty-five".