21312122002 has 8 divisors (see below), whose sum is σ = 31973380236. Its totient is φ = 10654328592.

The previous prime is 21312121997. The next prime is 21312122003. The reversal of 21312122002 is 20022121312.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 12828054121 + 8484067881 = 113261^2 + 92109^2 .

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

It is not an unprimeable number, because it can be changed into a prime (21312122003) 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 in 3 ways as a sum of consecutive naturals, for example, 850773 + ... + 875464.

Almost surely, 2^21312122002 is an apocalyptic number.

21312122002 is a deficient number, since it is larger than the sum of its proper divisors (10661258234).

21312122002 is a wasteful number, since it uses less digits than its factorization.

21312122002 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1732412.

The product of its (nonzero) digits is 96, while the sum is 16.

Adding to 21312122002 its reverse (20022121312), we get a palindrome (41334243314).

The spelling of 21312122002 in words is "twenty-one billion, three hundred twelve million, one hundred twenty-two thousand, two".