42931561 has 2 divisors, whose sum is σ = 42931562. Its totient is φ = 42931560.

The previous prime is 42931543. The next prime is 42931589. The reversal of 42931561 is 16513924.

42931561 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 39438400 + 3493161 = 6280^2 + 1869^2 .

It is a cyclic number.

It is not a de Polignac number, because 42931561 - 2⁵ = 42931529 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (42931541) 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 as a sum of consecutive naturals, namely, 21465780 + 21465781.

It is an arithmetic number, because the mean of its divisors is an integer number (21465781).

Almost surely, 2^42931561 is an apocalyptic number.

It is an amenable number.

42931561 is a deficient number, since it is larger than the sum of its proper divisors (1).

42931561 is an equidigital number, since it uses as much as digits as its factorization.

42931561 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 6480, while the sum is 31.

The square root of 42931561 is about 6552.2180214031. The cubic root of 42931561 is about 350.1538398539.

The spelling of 42931561 in words is "forty-two million, nine hundred thirty-one thousand, five hundred sixty-one".