21020121002 has 48 divisors (see below), whose sum is σ = 35380037952. Its totient is φ = 9332496000.

The previous prime is 21020120993. The next prime is 21020121007. The reversal of 21020121002 is 20012102012.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (21020121007) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 3077363 + ... + 3084185.

It is an arithmetic number, because the mean of its divisors is an integer number (737084124).

Almost surely, 2^21020121002 is an apocalyptic number.

21020121002 is a deficient number, since it is larger than the sum of its proper divisors (14359916950).

21020121002 is a wasteful number, since it uses less digits than its factorization.

21020121002 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7131 (or 7112 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 11.

Adding to 21020121002 its reverse (20012102012), we get a palindrome (41032223014).

The spelling of 21020121002 in words is "twenty-one billion, twenty million, one hundred twenty-one thousand, two".