42355561 has 2 divisors, whose sum is σ = 42355562. Its totient is φ = 42355560.

The previous prime is 42355543. The next prime is 42355589. The reversal of 42355561 is 16555324.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 40717161 + 1638400 = 6381^2 + 1280^2 .

It is a cyclic number.

It is not a de Polignac number, because 42355561 - 2⁷ = 42355433 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (42355961) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21177780 + 21177781.

It is an arithmetic number, because the mean of its divisors is an integer number (21177781).

Almost surely, 2^42355561 is an apocalyptic number.

It is an amenable number.

42355561 is a deficient number, since it is larger than the sum of its proper divisors (1).

42355561 is an equidigital number, since it uses as much as digits as its factorization.

42355561 is an evil number, because the sum of its binary digits is even.

The product of its digits is 18000, while the sum is 31.

The square root of 42355561 is about 6508.1150112763. The cubic root of 42355561 is about 348.5808137806.

The spelling of 42355561 in words is "forty-two million, three hundred fifty-five thousand, five hundred sixty-one".