42991291 has 4 divisors (see below), whose sum is σ = 49132912. Its totient is φ = 36849672.

The previous prime is 42991279. The next prime is 42991297. The reversal of 42991291 is 19219924.

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 42991291 - 2⁵ = 42991259 is a prime.

It is a super-2 number, since 2×42991291² = 3696502203693362, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 42991291.

It is not an unprimeable number, because it can be changed into a prime (42991297) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3070800 + ... + 3070813.

It is an arithmetic number, because the mean of its divisors is an integer number (12283228).

Almost surely, 2^42991291 is an apocalyptic number.

42991291 is a deficient number, since it is larger than the sum of its proper divisors (6141621).

42991291 is an equidigital number, since it uses as much as digits as its factorization.

42991291 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6141620.

The product of its digits is 11664, while the sum is 37.

The square root of 42991291 is about 6556.7744356505. The cubic root of 42991291 is about 350.3161524311.

The spelling of 42991291 in words is "forty-two million, nine hundred ninety-one thousand, two hundred ninety-one".