21021220002 has 16 divisors (see below), whose sum is σ = 42046899840. Its totient is φ = 7006330032.

The previous prime is 21021219883. The next prime is 21021220007. The reversal of 21021220002 is 20002212012.

It is a self number, because there is not a number n which added to its sum of digits gives 21021220002.

It is not an unprimeable number, because it can be changed into a prime (21021220007) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 122913 + ... + 239060.

It is an arithmetic number, because the mean of its divisors is an integer number (2627931240).

Almost surely, 2^21021220002 is an apocalyptic number.

21021220002 is an abundant number, since it is smaller than the sum of its proper divisors (21025679838).

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

21021220002 is a wasteful number, since it uses less digits than its factorization.

21021220002 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 371657.

The product of its (nonzero) digits is 32, while the sum is 12.

Adding to 21021220002 its reverse (20002212012), we get a palindrome (41023432014).

The spelling of 21021220002 in words is "twenty-one billion, twenty-one million, two hundred twenty thousand, two".