42415981 has 2 divisors, whose sum is σ = 42415982. Its totient is φ = 42415980.

The previous prime is 42415973. The next prime is 42416027. The reversal of 42415981 is 18951424.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 38862756 + 3553225 = 6234^2 + 1885^2 .

It is a cyclic number.

It is not a de Polignac number, because 42415981 - 2³ = 42415973 is a prime.

It is a super-2 number, since 2×42415981² = 3598230888384722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (42415181) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21207990 + 21207991.

It is an arithmetic number, because the mean of its divisors is an integer number (21207991).

Almost surely, 2^42415981 is an apocalyptic number.

It is an amenable number.

42415981 is a deficient number, since it is larger than the sum of its proper divisors (1).

42415981 is an equidigital number, since it uses as much as digits as its factorization.

42415981 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 11520, while the sum is 34.

The square root of 42415981 is about 6512.7552541148. The cubic root of 42415981 is about 348.7464846363.

The spelling of 42415981 in words is "forty-two million, four hundred fifteen thousand, nine hundred eighty-one".