21012120220202 has 4 divisors (see below), whose sum is σ = 31518180330306. Its totient is φ = 10506060110100.

The previous prime is 21012120220163. The next prime is 21012120220229. The reversal of 21012120220202 is 20202202121012.

It is a happy number.

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., 13311267668521 + 7700852551681 = 3648461^2 + 2775041^2 .

It is a super-2 number, since 2×21012120220202² (a number of 27 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5253030055049 + ... + 5253030055052.

Almost surely, 2^{21012120220202} is an apocalyptic number.

21012120220202 is a deficient number, since it is larger than the sum of its proper divisors (10506060110104).

21012120220202 is a wasteful number, since it uses less digits than its factorization.

21012120220202 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10506060110103.

The product of its (nonzero) digits is 128, while the sum is 17.

Adding to 21012120220202 its reverse (20202202121012), we get a palindrome (41214322341214).

The spelling of 21012120220202 in words is "twenty-one trillion, twelve billion, one hundred twenty million, two hundred twenty thousand, two hundred two".