21200121202 has 16 divisors (see below), whose sum is σ = 34252628760. Its totient is φ = 9782877312.

The previous prime is 21200121197. The next prime is 21200121203. The reversal of 21200121202 is 20212100212.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 12902915281 + 8297205921 = 113591^2 + 91089^2 .

It is a Harshad number since it is a multiple of its sum of digits (13).

It is not an unprimeable number, because it can be changed into a prime (21200121203) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 75478 + ... + 219310.

Almost surely, 2^21200121202 is an apocalyptic number.

21200121202 is a deficient number, since it is larger than the sum of its proper divisors (13052507558).

21200121202 is a wasteful number, since it uses less digits than its factorization.

21200121202 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 149517.

The product of its (nonzero) digits is 32, while the sum is 13.

Adding to 21200121202 its reverse (20212100212), we get a palindrome (41412221414).

The spelling of 21200121202 in words is "twenty-one billion, two hundred million, one hundred twenty-one thousand, two hundred two".