77777600042 has 4 divisors (see below), whose sum is σ = 116666400066. Its totient is φ = 38888800020.

The previous prime is 77777600041. The next prime is 77777600059. The reversal of 77777600042 is 24000677777.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 24000677777 = 8501 ⋅2823277.

It can be written as a sum of positive squares in only one way, i.e., 72818482801 + 4959117241 = 269849^2 + 70421^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 77777600042.

It is not an unprimeable number, because it can be changed into a prime (77777600041) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19444400009 + ... + 19444400012.

Almost surely, 2^77777600042 is an apocalyptic number.

77777600042 is a deficient number, since it is larger than the sum of its proper divisors (38888800024).

77777600042 is a wasteful number, since it uses less digits than its factorization.

77777600042 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38888800023.

The product of its (nonzero) digits is 806736, while the sum is 47.

The spelling of 77777600042 in words is "seventy-seven billion, seven hundred seventy-seven million, six hundred thousand, forty-two".