641541533561 has 32 divisors (see below), whose sum is σ = 678475284480. Its totient is φ = 606029255104.

The previous prime is 641541533513. The next prime is 641541533593. The reversal of 641541533561 is 165335145146.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-641541533561 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (641541523561) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 49407476 + ... + 49420458.

It is an arithmetic number, because the mean of its divisors is an integer number (21202352640).

Almost surely, 2^641541533561 is an apocalyptic number.

It is an amenable number.

641541533561 is a deficient number, since it is larger than the sum of its proper divisors (36933750919).

641541533561 is a wasteful number, since it uses less digits than its factorization.

641541533561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13405.

The product of its digits is 648000, while the sum is 44.

The spelling of 641541533561 in words is "six hundred forty-one billion, five hundred forty-one million, five hundred thirty-three thousand, five hundred sixty-one".