42009997 has 4 divisors (see below), whose sum is σ = 42330816. Its totient is φ = 41689180.

The previous prime is 42009971. The next prime is 42010013. The reversal of 42009997 is 79990024.

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 42009997 - 2¹¹ = 42007949 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (42009917) 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, 160213 + ... + 160474.

It is an arithmetic number, because the mean of its divisors is an integer number (10582704).

Almost surely, 2^42009997 is an apocalyptic number.

It is an amenable number.

42009997 is a deficient number, since it is larger than the sum of its proper divisors (320819).

42009997 is a wasteful number, since it uses less digits than its factorization.

42009997 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 320818.

The product of its (nonzero) digits is 40824, while the sum is 40.

The square root of 42009997 is about 6481.5119378120. The cubic root of 42009997 is about 347.6302415376.

The spelling of 42009997 in words is "forty-two million, nine thousand, nine hundred ninety-seven".