21002121031323 has 4 divisors (see below), whose sum is σ = 28002828041768. Its totient is φ = 14001414020880.

The previous prime is 21002121031313. The next prime is 21002121031327. The reversal of 21002121031323 is 32313012120012.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 21002121031323 - 2⁹ = 21002121030811 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21002121031323.

It is not an unprimeable number, because it can be changed into a prime (21002121031327) 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 3 ways as a sum of consecutive naturals, for example, 3500353505218 + ... + 3500353505223.

It is an arithmetic number, because the mean of its divisors is an integer number (7000707010442).

Almost surely, 2^{21002121031323} is an apocalyptic number.

21002121031323 is a deficient number, since it is larger than the sum of its proper divisors (7000707010445).

21002121031323 is an equidigital number, since it uses as much as digits as its factorization.

21002121031323 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7000707010444.

The product of its (nonzero) digits is 432, while the sum is 21.

Adding to 21002121031323 its reverse (32313012120012), we get a palindrome (53315133151335).

The spelling of 21002121031323 in words is "twenty-one trillion, two billion, one hundred twenty-one million, thirty-one thousand, three hundred twenty-three".