42778489 has 4 divisors (see below), whose sum is σ = 46069156. Its totient is φ = 39487824.

The previous prime is 42778487. The next prime is 42778513. The reversal of 42778489 is 98487724.

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

It can be written as a sum of positive squares in 2 ways, for example, as 6718464 + 36060025 = 2592^2 + 6005^2 .

It is a cyclic number.

It is not a de Polignac number, because 42778489 - 2¹ = 42778487 is a prime.

It is a super-2 number, since 2×42778489² = 3659998242246242, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (42778487) 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, 1645314 + ... + 1645339.

It is an arithmetic number, because the mean of its divisors is an integer number (11517289).

Almost surely, 2^42778489 is an apocalyptic number.

It is an amenable number.

42778489 is a deficient number, since it is larger than the sum of its proper divisors (3290667).

42778489 is a wasteful number, since it uses less digits than its factorization.

42778489 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3290666.

The product of its digits is 903168, while the sum is 49.

The square root of 42778489 is about 6540.5266607514. The cubic root of 42778489 is about 349.7371877397.

The spelling of 42778489 in words is "forty-two million, seven hundred seventy-eight thousand, four hundred eighty-nine".