21001020202 has 8 divisors (see below), whose sum is σ = 31502967300. Its totient is φ = 10500031104.

The previous prime is 21001020197. The next prime is 21001020223. The reversal of 21001020202 is 20202010012.

It can be written as a sum of positive squares in 2 ways, for example, as 20989924641 + 11095561 = 144879^2 + 3331^2 .

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

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 181927 + ... + 274042.

Almost surely, 2^21001020202 is an apocalyptic number.

21001020202 is a deficient number, since it is larger than the sum of its proper divisors (10501947098).

21001020202 is a wasteful number, since it uses less digits than its factorization.

21001020202 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 479000.

The product of its (nonzero) digits is 16, while the sum is 10.

Adding to 21001020202 its reverse (20202010012), we get a palindrome (41203030214).

The spelling of 21001020202 in words is "twenty-one billion, one million, twenty thousand, two hundred two".