21216351120530 has 8 divisors (see below), whose sum is σ = 38189432016972. Its totient is φ = 8486540448208.

The previous prime is 21216351120527. The next prime is 21216351120539. The reversal of 21216351120530 is 3502115361212.

It can be written as a sum of positive squares in 2 ways, for example, as 21137843003281 + 78508117249 = 4597591^2 + 280193^2 .

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

It is a super-2 number, since 2×21216351120530² (a number of 27 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21216351120539) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1060817556017 + ... + 1060817556036.

Almost surely, 2^{21216351120530} is an apocalyptic number.

21216351120530 is a deficient number, since it is larger than the sum of its proper divisors (16973080896442).

21216351120530 is a wasteful number, since it uses less digits than its factorization.

21216351120530 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2121635112060.

The product of its (nonzero) digits is 10800, while the sum is 32.

Adding to 21216351120530 its reverse (3502115361212), we get a palindrome (24718466481742).

The spelling of 21216351120530 in words is "twenty-one trillion, two hundred sixteen billion, three hundred fifty-one million, one hundred twenty thousand, five hundred thirty".