77961655 has 8 divisors (see below), whose sum is σ = 98478000. Its totient is φ = 59086656.

The previous prime is 77961649. The next prime is 77961659. The reversal of 77961655 is 55616977.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 77961655 - 2¹⁷ = 77830583 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77961659) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 410230 + ... + 410419.

It is an arithmetic number, because the mean of its divisors is an integer number (12309750).

Almost surely, 2^77961655 is an apocalyptic number.

77961655 is a deficient number, since it is larger than the sum of its proper divisors (20516345).

77961655 is a wasteful number, since it uses less digits than its factorization.

77961655 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 820673.

The product of its digits is 396900, while the sum is 46.

The square root of 77961655 is about 8829.5897413187. The cubic root of 77961655 is about 427.1958416947.

The spelling of 77961655 in words is "seventy-seven million, nine hundred sixty-one thousand, six hundred fifty-five".