76765561 has 4 divisors (see below), whose sum is σ = 76948324. Its totient is φ = 76582800.

The previous prime is 76765553. The next prime is 76765583. The reversal of 76765561 is 16556767.

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 1336336 + 75429225 = 1156^2 + 8685^2 .

It is a cyclic number.

It is not a de Polignac number, because 76765561 - 2³ = 76765553 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (76765061) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 90750 + ... + 91591.

It is an arithmetic number, because the mean of its divisors is an integer number (19237081).

Almost surely, 2^76765561 is an apocalyptic number.

It is an amenable number.

76765561 is a deficient number, since it is larger than the sum of its proper divisors (182763).

76765561 is a wasteful number, since it uses less digits than its factorization.

76765561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 182762.

The product of its digits is 264600, while the sum is 43.

The square root of 76765561 is about 8761.5958021356. The cubic root of 76765561 is about 424.9998818915. Note that the first 3 decimals are identical.

The spelling of 76765561 in words is "seventy-six million, seven hundred sixty-five thousand, five hundred sixty-one".