21002121210999 has 16 divisors (see below), whose sum is σ = 28107103117824. Its totient is φ = 13949293108800.

The previous prime is 21002121210997. The next prime is 21002121211033. The reversal of 21002121210999 is 99901212120012.

It is a happy number.

It is not a de Polignac number, because 21002121210999 - 2¹ = 21002121210997 is a prime.

It is a super-2 number, since 2×21002121210999² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21002121210991) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3089602 + ... + 7179824.

It is an arithmetic number, because the mean of its divisors is an integer number (1756693944864).

Almost surely, 2^{21002121210999} is an apocalyptic number.

21002121210999 is a deficient number, since it is larger than the sum of its proper divisors (7104981906825).

21002121210999 is a wasteful number, since it uses less digits than its factorization.

21002121210999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4096598.

The product of its (nonzero) digits is 11664, while the sum is 39.

The spelling of 21002121210999 in words is "twenty-one trillion, two billion, one hundred twenty-one million, two hundred ten thousand, nine hundred ninety-nine".