42778786 has 4 divisors (see below), whose sum is σ = 64168182. Its totient is φ = 21389392.

The previous prime is 42778777. The next prime is 42778811. The reversal of 42778786 is 68787724.

It is a happy number.

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

It can be written as a sum of positive squares in only one way, i.e., 42315025 + 463761 = 6505^2 + 681^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10694695 + ... + 10694698.

Almost surely, 2^42778786 is an apocalyptic number.

42778786 is a deficient number, since it is larger than the sum of its proper divisors (21389396).

42778786 is a wasteful number, since it uses less digits than its factorization.

42778786 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21389395.

The product of its digits is 1053696, while the sum is 49.

The square root of 42778786 is about 6540.5493653056. The cubic root of 42778786 is about 349.7379971162.

The spelling of 42778786 in words is "forty-two million, seven hundred seventy-eight thousand, seven hundred eighty-six".