77465816561 has 16 divisors (see below), whose sum is σ = 90443005440. Its totient is φ = 64967132160.

The previous prime is 77465816453. The next prime is 77465816573. The reversal of 77465816561 is 16561856477.

It is a happy number.

It is not a de Polignac number, because 77465816561 - 2¹⁴ = 77465800177 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 77465816497 and 77465816506.

It is not an unprimeable number, because it can be changed into a prime (77465818561) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1127681 + ... + 1194401.

It is an arithmetic number, because the mean of its divisors is an integer number (5652687840).

Almost surely, 2^77465816561 is an apocalyptic number.

It is an amenable number.

77465816561 is a deficient number, since it is larger than the sum of its proper divisors (12977188879).

77465816561 is a wasteful number, since it uses less digits than its factorization.

77465816561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 70304.

The product of its digits is 8467200, while the sum is 56.

The spelling of 77465816561 in words is "seventy-seven billion, four hundred sixty-five million, eight hundred sixteen thousand, five hundred sixty-one".