42117561 has 12 divisors (see below), whose sum is σ = 62799360. Its totient is φ = 27172440.

The previous prime is 42117557. The next prime is 42117583. The reversal of 42117561 is 16571124.

It is a happy number.

It is not a de Polignac number, because 42117561 - 2² = 42117557 is a prime.

It is not an unprimeable number, because it can be changed into a prime (42117161) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 75201 + ... + 75758.

It is an arithmetic number, because the mean of its divisors is an integer number (5233280).

Almost surely, 2^42117561 is an apocalyptic number.

It is an amenable number.

42117561 is a deficient number, since it is larger than the sum of its proper divisors (20681799).

42117561 is a wasteful number, since it uses less digits than its factorization.

42117561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 150996 (or 150993 counting only the distinct ones).

The product of its digits is 1680, while the sum is 27.

The square root of 42117561 is about 6489.8043884234. The cubic root of 42117561 is about 347.9266839208.

Adding to 42117561 its reverse (16571124), we get a palindrome (58688685).

The spelling of 42117561 in words is "forty-two million, one hundred seventeen thousand, five hundred sixty-one".