42155779 has 4 divisors (see below), whose sum is σ = 42290776. Its totient is φ = 42020784.

The previous prime is 42155761. The next prime is 42155807. The reversal of 42155779 is 97755124.

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 42155779 - 2⁵ = 42155747 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (42155719) 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, 67029 + ... + 67654.

It is an arithmetic number, because the mean of its divisors is an integer number (10572694).

Almost surely, 2^42155779 is an apocalyptic number.

42155779 is a deficient number, since it is larger than the sum of its proper divisors (134997).

42155779 is a wasteful number, since it uses less digits than its factorization.

42155779 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 134996.

The product of its digits is 88200, while the sum is 40.

The square root of 42155779 is about 6492.7481854759. The cubic root of 42155779 is about 348.0318897759.

The spelling of 42155779 in words is "forty-two million, one hundred fifty-five thousand, seven hundred seventy-nine".