42778787 has 4 divisors (see below), whose sum is σ = 42797136. Its totient is φ = 42760440.

The previous prime is 42778777. The next prime is 42778811. The reversal of 42778787 is 78787724.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-42778787 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (42778777) 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, 5063 + ... + 10544.

It is an arithmetic number, because the mean of its divisors is an integer number (10699284).

Almost surely, 2^42778787 is an apocalyptic number.

42778787 is a deficient number, since it is larger than the sum of its proper divisors (18349).

42778787 is a wasteful number, since it uses less digits than its factorization.

42778787 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18348.

The product of its digits is 1229312, while the sum is 50.

The square root of 42778787 is about 6540.5494417518. The cubic root of 42778787 is about 349.7379998414.

The spelling of 42778787 in words is "forty-two million, seven hundred seventy-eight thousand, seven hundred eighty-seven".