42120217 has 2 divisors, whose sum is σ = 42120218. Its totient is φ = 42120216.

The previous prime is 42120191. The next prime is 42120233. The reversal of 42120217 is 71202124.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 24049216 + 18071001 = 4904^2 + 4251^2 .

It is a cyclic number.

It is not a de Polignac number, because 42120217 - 2¹⁵ = 42087449 is a prime.

It is a super-2 number, since 2×42120217² = 3548225360254178, which contains 22 as substring.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 42120194 and 42120203.

It is not a weakly prime, because it can be changed into another prime (42120517) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21060108 + 21060109.

It is an arithmetic number, because the mean of its divisors is an integer number (21060109).

Almost surely, 2^42120217 is an apocalyptic number.

It is an amenable number.

42120217 is a deficient number, since it is larger than the sum of its proper divisors (1).

42120217 is an equidigital number, since it uses as much as digits as its factorization.

42120217 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 224, while the sum is 19.

The square root of 42120217 is about 6490.0090138612. The cubic root of 42120217 is about 347.9339973694.

The spelling of 42120217 in words is "forty-two million, one hundred twenty thousand, two hundred seventeen".