42138577 has 4 divisors (see below), whose sum is σ = 45380020. Its totient is φ = 38897136.

The previous prime is 42138559. The next prime is 42138587. The reversal of 42138577 is 77583124.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 19395216 + 22743361 = 4404^2 + 4769^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-42138577 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (42138527) 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, 1620702 + ... + 1620727.

It is an arithmetic number, because the mean of its divisors is an integer number (11345005).

Almost surely, 2^42138577 is an apocalyptic number.

It is an amenable number.

42138577 is a deficient number, since it is larger than the sum of its proper divisors (3241443).

42138577 is a wasteful number, since it uses less digits than its factorization.

42138577 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3241442.

The product of its digits is 47040, while the sum is 37.

The square root of 42138577 is about 6491.4233416101. The cubic root of 42138577 is about 347.9845442777.

The spelling of 42138577 in words is "forty-two million, one hundred thirty-eight thousand, five hundred seventy-seven".