42779909 has 4 divisors (see below), whose sum is σ = 42796320. Its totient is φ = 42763500.

The previous prime is 42779903. The next prime is 42779911. The reversal of 42779909 is 90997724.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-42779909 is a prime.

It is a super-2 number, since 2×42779909² = 3660241228096562, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (42779903) 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, 3329 + ... + 9830.

It is an arithmetic number, because the mean of its divisors is an integer number (10699080).

Almost surely, 2^42779909 is an apocalyptic number.

It is an amenable number.

42779909 is a deficient number, since it is larger than the sum of its proper divisors (16411).

42779909 is a wasteful number, since it uses less digits than its factorization.

42779909 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16410.

The product of its (nonzero) digits is 285768, while the sum is 47.

The square root of 42779909 is about 6540.6352138000. The cubic root of 42779909 is about 349.7410574519.

The spelling of 42779909 in words is "forty-two million, seven hundred seventy-nine thousand, nine hundred nine".