77001661 has 12 divisors (see below), whose sum is σ = 88660224. Its totient is φ = 66313800.

The previous prime is 77001647. The next prime is 77001671. The reversal of 77001661 is 16610077.

It is not a de Polignac number, because 77001661 - 2⁵ = 77001629 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 (77001601) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 5725 + ... + 13666.

It is an arithmetic number, because the mean of its divisors is an integer number (7388352).

Almost surely, 2^77001661 is an apocalyptic number.

It is an amenable number.

77001661 is a deficient number, since it is larger than the sum of its proper divisors (11658563).

77001661 is a wasteful number, since it uses less digits than its factorization.

77001661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19440 (or 19421 counting only the distinct ones).

The product of its (nonzero) digits is 1764, while the sum is 28.

The square root of 77001661 is about 8775.0590311405. The cubic root of 77001661 is about 425.4351455488.

It can be divided in two parts, 770016 and 61, that added together give a palindrome (770077).

The spelling of 77001661 in words is "seventy-seven million, one thousand, six hundred sixty-one".