21012121121002 has 72 divisors (see below), whose sum is σ = 35805358130724. Its totient is φ = 9240852297600.

The previous prime is 21012121120999. The next prime is 21012121121003. The reversal of 21012121121002 is 20012112121012.

It can be written as a sum of positive squares in 2 ways, for example, as 19233496131201 + 1778624989801 = 4385601^2 + 1333651^2 .

It is not an unprimeable number, because it can be changed into a prime (21012121121003) 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 35 ways as a sum of consecutive naturals, for example, 1686765958 + ... + 1686778414.

Almost surely, 2^{21012121121002} is an apocalyptic number.

21012121121002 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

21012121121002 is a deficient number, since it is larger than the sum of its proper divisors (14793237009722).

21012121121002 is a wasteful number, since it uses less digits than its factorization.

21012121121002 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19796 (or 19754 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 16.

Adding to 21012121121002 its reverse (20012112121012), we get a palindrome (41024233242014).

The spelling of 21012121121002 in words is "twenty-one trillion, twelve billion, one hundred twenty-one million, one hundred twenty-one thousand, two".