77681018 has 8 divisors (see below), whose sum is σ = 116728020. Its totient is φ = 38771680.

The previous prime is 77681017. The next prime is 77681027. The reversal of 77681018 is 81018677.

It can be written as a sum of positive squares in 2 ways, for example, as 58171129 + 19509889 = 7627^2 + 4417^2 .

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

It is not an unprimeable number, because it can be changed into a prime (77681017) 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, 32993 + ... + 35268.

Almost surely, 2^77681018 is an apocalyptic number.

77681018 is a deficient number, since it is larger than the sum of its proper divisors (39047002).

77681018 is a wasteful number, since it uses less digits than its factorization.

77681018 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 68832.

The product of its (nonzero) digits is 18816, while the sum is 38.

The square root of 77681018 is about 8813.6835659105. The cubic root of 77681018 is about 426.6826359854.

The spelling of 77681018 in words is "seventy-seven million, six hundred eighty-one thousand, eighteen".