42343981 has 2 divisors, whose sum is σ = 42343982. Its totient is φ = 42343980.

The previous prime is 42343937. The next prime is 42343997. The reversal of 42343981 is 18934324.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 39312900 + 3031081 = 6270^2 + 1741^2 .

It is a cyclic number.

It is not a de Polignac number, because 42343981 - 2²³ = 33955373 is a prime.

It is a super-2 number, since 2×42343981² = 3586025453856722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (42343901) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21171990 + 21171991.

It is an arithmetic number, because the mean of its divisors is an integer number (21171991).

Almost surely, 2^42343981 is an apocalyptic number.

It is an amenable number.

42343981 is a deficient number, since it is larger than the sum of its proper divisors (1).

42343981 is an equidigital number, since it uses as much as digits as its factorization.

42343981 is an evil number, because the sum of its binary digits is even.

The product of its digits is 20736, while the sum is 34.

The square root of 42343981 is about 6507.2252919351. The cubic root of 42343981 is about 348.5490435821.

The spelling of 42343981 in words is "forty-two million, three hundred forty-three thousand, nine hundred eighty-one".