42117409 has 2 divisors, whose sum is σ = 42117410. Its totient is φ = 42117408.

The previous prime is 42117377. The next prime is 42117469. The reversal of 42117409 is 90471124.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 30747025 + 11370384 = 5545^2 + 3372^2 .

It is a cyclic number.

It is not a de Polignac number, because 42117409 - 2⁵ = 42117377 is a prime.

It is a super-2 number, since 2×42117409² = 3547752281746562, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (42117469) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21058704 + 21058705.

It is an arithmetic number, because the mean of its divisors is an integer number (21058705).

Almost surely, 2^42117409 is an apocalyptic number.

It is an amenable number.

42117409 is a deficient number, since it is larger than the sum of its proper divisors (1).

42117409 is an equidigital number, since it uses as much as digits as its factorization.

42117409 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2016, while the sum is 28.

The square root of 42117409 is about 6489.7926777363. The cubic root of 42117409 is about 347.9262653708.

The spelling of 42117409 in words is "forty-two million, one hundred seventeen thousand, four hundred nine".