202121001205 has 4 divisors (see below), whose sum is σ = 242545201452. Its totient is φ = 161696800960.

The previous prime is 202121001149. The next prime is 202121001209. The reversal of 202121001205 is 502100121202.

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 2 ways, for example, as 90152464516 + 111968536689 = 300254^2 + 334617^2 .

It is not a de Polignac number, because 202121001205 - 2⁷ = 202121001077 is a prime.

It is a super-2 number, since 2×202121001205² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (202121001209) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 20212100116 + ... + 20212100125.

It is an arithmetic number, because the mean of its divisors is an integer number (60636300363).

Almost surely, 2^202121001205 is an apocalyptic number.

It is an amenable number.

202121001205 is a deficient number, since it is larger than the sum of its proper divisors (40424200247).

202121001205 is an equidigital number, since it uses as much as digits as its factorization.

202121001205 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40424200246.

The product of its (nonzero) digits is 80, while the sum is 16.

Adding to 202121001205 its reverse (502100121202), we get a palindrome (704221122407).

The spelling of 202121001205 in words is "two hundred two billion, one hundred twenty-one million, one thousand, two hundred five".