42305981 has 4 divisors (see below), whose sum is σ = 42701472. Its totient is φ = 41910492.

The previous prime is 42305959. The next prime is 42305987. The reversal of 42305981 is 18950324.

42305981 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 42305981 - 2¹⁰ = 42304957 is a prime.

It is a super-2 number, since 2×42305981² = 3579592056744722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (42305987) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 197585 + ... + 197798.

It is an arithmetic number, because the mean of its divisors is an integer number (10675368).

Almost surely, 2^42305981 is an apocalyptic number.

It is an amenable number.

42305981 is a deficient number, since it is larger than the sum of its proper divisors (395491).

42305981 is a wasteful number, since it uses less digits than its factorization.

42305981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 395490.

The product of its (nonzero) digits is 8640, while the sum is 32.

The square root of 42305981 is about 6504.3048052809. The cubic root of 42305981 is about 348.4447483367. Note that the first 3 decimals are identical.

The spelling of 42305981 in words is "forty-two million, three hundred five thousand, nine hundred eighty-one".