21212033242 has 4 divisors (see below), whose sum is σ = 31818049866. Its totient is φ = 10606016620.

The previous prime is 21212033197. The next prime is 21212033261. The reversal of 21212033242 is 24233021212.

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., 17500908681 + 3711124561 = 132291^2 + 60919^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5303008309 + ... + 5303008312.

Almost surely, 2^21212033242 is an apocalyptic number.

21212033242 is a deficient number, since it is larger than the sum of its proper divisors (10606016624).

21212033242 is a wasteful number, since it uses less digits than its factorization.

21212033242 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10606016623.

The product of its (nonzero) digits is 1152, while the sum is 22.

Adding to 21212033242 its reverse (24233021212), we get a palindrome (45445054454).

The spelling of 21212033242 in words is "twenty-one billion, two hundred twelve million, thirty-three thousand, two hundred forty-two".