77666442 has 16 divisors (see below), whose sum is σ = 177523392. Its totient is φ = 22190400.

The previous prime is 77666431. The next prime is 77666443. The reversal of 77666442 is 24466677.

It is a Harshad number since it is a multiple of its sum of digits (42), and also a Moran number because the ratio is a prime number: 1849201 = 77666442 / (7 + 7 + 6 + 6 + 6 + 4 + 4 + 2).

It is a nialpdrome in base 10.

It is a junction number, because it is equal to n+sod(n) for n = 77666394 and 77666403.

It is not an unprimeable number, because it can be changed into a prime (77666443) 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, 924559 + ... + 924642.

It is an arithmetic number, because the mean of its divisors is an integer number (11095212).

Almost surely, 2^77666442 is an apocalyptic number.

77666442 is an abundant number, since it is smaller than the sum of its proper divisors (99856950).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

77666442 is a wasteful number, since it uses less digits than its factorization.

77666442 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1849213.

The product of its digits is 338688, while the sum is 42.

The square root of 77666442 is about 8812.8566310817. The cubic root of 77666442 is about 426.6559468607.

The spelling of 77666442 in words is "seventy-seven million, six hundred sixty-six thousand, four hundred forty-two".