211840042 has 8 divisors (see below), whose sum is σ = 317826756. Its totient is φ = 105897792.

The previous prime is 211840039. The next prime is 211840049. The reversal of 211840042 is 240048112.

It can be written as a sum of positive squares in 2 ways, for example, as 191850201 + 19989841 = 13851^2 + 4471^2 .

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 = 211839995 and 211840022.

It is not an unprimeable number, because it can be changed into a prime (211840049) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6178 + ... + 21490.

Almost surely, 2^211840042 is an apocalyptic number.

211840042 is a deficient number, since it is larger than the sum of its proper divisors (105986714).

211840042 is a wasteful number, since it uses less digits than its factorization.

211840042 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22232.

The product of its (nonzero) digits is 512, while the sum is 22.

The square root of 211840042 is about 14554.7257617586. The cubic root of 211840042 is about 596.1231915822.

Adding to 211840042 its reverse (240048112), we get a palindrome (451888154).

The spelling of 211840042 in words is "two hundred eleven million, eight hundred forty thousand, forty-two".