215021320042 has 4 divisors (see below), whose sum is σ = 322531980066. Its totient is φ = 107510660020.

The previous prime is 215021320037. The next prime is 215021320043. The reversal of 215021320042 is 240023120512.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 171852531601 + 43168788441 = 414551^2 + 207771^2 .

It is a junction number, because it is equal to n+sod(n) for n = 215021319995 and 215021320022.

It is not an unprimeable number, because it can be changed into a prime (215021320043) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 53755330009 + ... + 53755330012.

Almost surely, 2^215021320042 is an apocalyptic number.

215021320042 is a deficient number, since it is larger than the sum of its proper divisors (107510660024).

215021320042 is a wasteful number, since it uses less digits than its factorization.

215021320042 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 107510660023.

The product of its (nonzero) digits is 960, while the sum is 22.

Adding to 215021320042 its reverse (240023120512), we get a palindrome (455044440554).

The spelling of 215021320042 in words is "two hundred fifteen billion, twenty-one million, three hundred twenty thousand, forty-two".