520777661 has 4 divisors (see below), whose sum is σ = 543420192. Its totient is φ = 498135132.

The previous prime is 520777657. The next prime is 520777681. The reversal of 520777661 is 166777025.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 520777661 - 2² = 520777657 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (520777681) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11321231 + ... + 11321276.

It is an arithmetic number, because the mean of its divisors is an integer number (135855048).

Almost surely, 2^520777661 is an apocalyptic number.

It is an amenable number.

520777661 is a deficient number, since it is larger than the sum of its proper divisors (22642531).

520777661 is a wasteful number, since it uses less digits than its factorization.

520777661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22642530.

The product of its (nonzero) digits is 123480, while the sum is 41.

The square root of 520777661 is about 22820.5534770741. The cubic root of 520777661 is about 804.5458189249.

The spelling of 520777661 in words is "five hundred twenty million, seven hundred seventy-seven thousand, six hundred sixty-one".