217405042 has 8 divisors (see below), whose sum is σ = 334061532. Its totient is φ = 106051200.

The previous prime is 217405009. The next prime is 217405051. The reversal of 217405042 is 240504712.

It can be written as a sum of positive squares in 2 ways, for example, as 144456361 + 72948681 = 12019^2 + 8541^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a junction number, because it is equal to n+sod(n) for n = 217404998 and 217405016.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1325559 + ... + 1325722.

Almost surely, 2^217405042 is an apocalyptic number.

217405042 is a deficient number, since it is larger than the sum of its proper divisors (116656490).

217405042 is a wasteful number, since it uses less digits than its factorization.

217405042 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2651324.

The product of its (nonzero) digits is 2240, while the sum is 25.

The square root of 217405042 is about 14744.6614745812. The cubic root of 217405042 is about 601.2981541157.

Adding to 217405042 its reverse (240504712), we get a palindrome (457909754).

The spelling of 217405042 in words is "two hundred seventeen million, four hundred five thousand, forty-two".