42891917 has 4 divisors (see below), whose sum is σ = 44051196. Its totient is φ = 41732640.

The previous prime is 42891907. The next prime is 42891923. The reversal of 42891917 is 71919824.

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 16410601 + 26481316 = 4051^2 + 5146^2 .

It is a cyclic number.

It is not a de Polignac number, because 42891917 - 2⁶ = 42891853 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (42891907) 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, 579584 + ... + 579657.

It is an arithmetic number, because the mean of its divisors is an integer number (11012799).

Almost surely, 2^42891917 is an apocalyptic number.

It is an amenable number.

42891917 is a deficient number, since it is larger than the sum of its proper divisors (1159279).

42891917 is a wasteful number, since it uses less digits than its factorization.

42891917 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1159278.

The product of its digits is 36288, while the sum is 41.

The square root of 42891917 is about 6549.1920875784. The cubic root of 42891917 is about 350.0460266001.

The spelling of 42891917 in words is "forty-two million, eight hundred ninety-one thousand, nine hundred seventeen".