21021011002 has 4 divisors (see below), whose sum is σ = 31531516506. Its totient is φ = 10510505500.

The previous prime is 21021010961. The next prime is 21021011027. The reversal of 21021011002 is 20011012012.

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., 18719986041 + 2301024961 = 136821^2 + 47969^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 21021011002.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5255252749 + ... + 5255252752.

Almost surely, 2^21021011002 is an apocalyptic number.

21021011002 is a deficient number, since it is larger than the sum of its proper divisors (10510505504).

21021011002 is a wasteful number, since it uses less digits than its factorization.

21021011002 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10510505503.

The product of its (nonzero) digits is 8, while the sum is 10.

Adding to 21021011002 its reverse (20011012012), we get a palindrome (41032023014).

The spelling of 21021011002 in words is "twenty-one billion, twenty-one million, eleven thousand, two".