42505987 has 4 divisors (see below), whose sum is σ = 42618520. Its totient is φ = 42393456.

The previous prime is 42505979. The next prime is 42505993. The reversal of 42505987 is 78950524.

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 42505987 - 2³ = 42505979 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (42505997) 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, 55698 + ... + 56455.

It is an arithmetic number, because the mean of its divisors is an integer number (10654630).

Almost surely, 2^42505987 is an apocalyptic number.

42505987 is a deficient number, since it is larger than the sum of its proper divisors (112533).

42505987 is a wasteful number, since it uses less digits than its factorization.

42505987 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 112532.

The product of its (nonzero) digits is 100800, while the sum is 40.

The square root of 42505987 is about 6519.6615709713. The cubic root of 42505987 is about 348.9929884224.

The spelling of 42505987 in words is "forty-two million, five hundred five thousand, nine hundred eighty-seven".