21020220202 has 4 divisors (see below), whose sum is σ = 31530330306. Its totient is φ = 10510110100.

The previous prime is 21020220167. The next prime is 21020220211. The reversal of 21020220202 is 20202202012.

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., 13637801961 + 7382418241 = 116781^2 + 85921^2 .

It is a super-3 number, since 3×21020220202³ (a number of 32 digits) contains 333 as substring.

It is a Smith number, since the sum of its digits (13) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5255055049 + ... + 5255055052.

Almost surely, 2^21020220202 is an apocalyptic number.

21020220202 is a deficient number, since it is larger than the sum of its proper divisors (10510110104).

21020220202 is a wasteful number, since it uses less digits than its factorization.

21020220202 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10510110103.

The product of its (nonzero) digits is 64, while the sum is 13.

Adding to 21020220202 its reverse (20202202012), we get a palindrome (41222422214).

The spelling of 21020220202 in words is "twenty-one billion, twenty million, two hundred twenty thousand, two hundred two".