42543517 has 2 divisors, whose sum is σ = 42543518. Its totient is φ = 42543516.

The previous prime is 42543511. The next prime is 42543533. The reversal of 42543517 is 71534524.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 41847961 + 695556 = 6469^2 + 834^2 .

It is a cyclic number.

It is not a de Polignac number, because 42543517 - 2³ = 42543509 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (42543511) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21271758 + 21271759.

It is an arithmetic number, because the mean of its divisors is an integer number (21271759).

Almost surely, 2^42543517 is an apocalyptic number.

It is an amenable number.

42543517 is a deficient number, since it is larger than the sum of its proper divisors (1).

42543517 is an equidigital number, since it uses as much as digits as its factorization.

42543517 is an evil number, because the sum of its binary digits is even.

The product of its digits is 16800, while the sum is 31.

The square root of 42543517 is about 6522.5391528146. The cubic root of 42543517 is about 349.0956708512.

The spelling of 42543517 in words is "forty-two million, five hundred forty-three thousand, five hundred seventeen".