42777779 has 4 divisors (see below), whose sum is σ = 46666680. Its totient is φ = 38888880.

The previous prime is 42777767. The next prime is 42777793. The reversal of 42777779 is 97777724.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 42777779 - 2²⁴ = 26000563 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (42777479) 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, 1944434 + ... + 1944455.

It is an arithmetic number, because the mean of its divisors is an integer number (11666670).

Almost surely, 2^42777779 is an apocalyptic number.

42777779 is a deficient number, since it is larger than the sum of its proper divisors (3888901).

42777779 is a wasteful number, since it uses less digits than its factorization.

42777779 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3888900.

The product of its digits is 1210104, while the sum is 50.

The square root of 42777779 is about 6540.4723835515. The cubic root of 42777779 is about 349.7352528516.

Subtracting 42777779 from its reverse (97777724), we obtain a palindrome (54999945).

The spelling of 42777779 in words is "forty-two million, seven hundred seventy-seven thousand, seven hundred seventy-nine".