21021240002 has 20 divisors (see below), whose sum is σ = 36784989606. Its totient is φ = 9009100800.

The previous prime is 21021240001. The next prime is 21021240029. The reversal of 21021240002 is 20004212012.

It can be written as a sum of positive squares in only one way, i.e., 19488439201 + 1532800801 = 139601^2 + 39151^2 .

It is a Harshad number since it is a multiple of its sum of digits (14).

It is not an unprimeable number, because it can be changed into a prime (21021240001) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 2183999 + ... + 2193602.

Almost surely, 2^21021240002 is an apocalyptic number.

21021240002 is a deficient number, since it is larger than the sum of its proper divisors (15763749604).

21021240002 is an frugal number, since it uses more digits than its factorization.

21021240002 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4377631 (or 4377610 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 14.

Adding to 21021240002 its reverse (20004212012), we get a palindrome (41025452014).

The spelling of 21021240002 in words is "twenty-one billion, twenty-one million, two hundred forty thousand, two".