42789979 has 4 divisors (see below), whose sum is σ = 42836584. Its totient is φ = 42743376.

The previous prime is 42789953. The next prime is 42789991. The reversal of 42789979 is 97998724.

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 42789979 - 2⁵ = 42789947 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (42789949) 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, 21897 + ... + 23770.

It is an arithmetic number, because the mean of its divisors is an integer number (10709146).

Almost surely, 2^42789979 is an apocalyptic number.

42789979 is a deficient number, since it is larger than the sum of its proper divisors (46605).

42789979 is an equidigital number, since it uses as much as digits as its factorization.

42789979 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 46604.

The product of its digits is 2286144, while the sum is 55.

The square root of 42789979 is about 6541.4049714110. The cubic root of 42789979 is about 349.7684972495.

The spelling of 42789979 in words is "forty-two million, seven hundred eighty-nine thousand, nine hundred seventy-nine".