42155709 has 4 divisors (see below), whose sum is σ = 56207616. Its totient is φ = 28103804.

The previous prime is 42155693. The next prime is 42155713. The reversal of 42155709 is 90755124.

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 not a de Polignac number, because 42155709 - 2⁴ = 42155693 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 42155709.

It is a congruent 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, 7025949 + ... + 7025954.

It is an arithmetic number, because the mean of its divisors is an integer number (14051904).

Almost surely, 2^42155709 is an apocalyptic number.

It is an amenable number.

42155709 is a deficient number, since it is larger than the sum of its proper divisors (14051907).

42155709 is a wasteful number, since it uses less digits than its factorization.

42155709 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14051906.

The product of its (nonzero) digits is 12600, while the sum is 33.

The square root of 42155709 is about 6492.7427948441. The cubic root of 42155709 is about 348.0316971392.

The spelling of 42155709 in words is "forty-two million, one hundred fifty-five thousand, seven hundred nine".