516561441554645 has 4 divisors (see below), whose sum is σ = 619873729865580. Its totient is φ = 413249153243712.

The previous prime is 516561441554581. The next prime is 516561441554701. The reversal of 516561441554645 is 546455144165615.

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 405558739203121 + 111002702351524 = 20138489^2 + 10535782^2 .

It is a cyclic number.

It is not a de Polignac number, because 516561441554645 - 2⁶ = 516561441554581 is a prime.

It is a congruent 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, 51656144155460 + ... + 51656144155469.

It is an arithmetic number, because the mean of its divisors is an integer number (154968432466395).

Almost surely, 2^{516561441554645} is an apocalyptic number.

It is an amenable number.

516561441554645 is a deficient number, since it is larger than the sum of its proper divisors (103312288310935).

516561441554645 is a wasteful number, since it uses less digits than its factorization.

516561441554645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 103312288310934.

The product of its digits is 172800000, while the sum is 62.

The spelling of 516561441554645 in words is "five hundred sixteen trillion, five hundred sixty-one billion, four hundred forty-one million, five hundred fifty-four thousand, six hundred forty-five".