21312244002 has 64 divisors (see below), whose sum is σ = 50365292544. Its totient is φ = 5883390720.

The previous prime is 21312244001. The next prime is 21312244003. The reversal of 21312244002 is 20044221312.

It is an interprime number because it is at equal distance from previous prime (21312244001) and next prime (21312244003).

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a self number, because there is not a number n which added to its sum of digits gives 21312244002.

It is not an unprimeable number, because it can be changed into a prime (21312244001) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 824458 + ... + 849914.

It is an arithmetic number, because the mean of its divisors is an integer number (786957696).

Almost surely, 2^21312244002 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21312244002, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25182646272).

21312244002 is an abundant number, since it is smaller than the sum of its proper divisors (29053048542).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21312244002 is a wasteful number, since it uses less digits than its factorization.

21312244002 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26143.

The product of its (nonzero) digits is 768, while the sum is 21.

Adding to 21312244002 its reverse (20044221312), we get a palindrome (41356465314).

The spelling of 21312244002 in words is "twenty-one billion, three hundred twelve million, two hundred forty-four thousand, two".