21002121353305 has 16 divisors (see below), whose sum is σ = 25738978443264. Its totient is φ = 16444080993600.

The previous prime is 21002121353287. The next prime is 21002121353413. The reversal of 21002121353305 is 50335312120012.

It is not a de Polignac number, because 21002121353305 - 2¹³ = 21002121345113 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 36835579 + ... + 37401391.

It is an arithmetic number, because the mean of its divisors is an integer number (1608686152704).

Almost surely, 2^{21002121353305} is an apocalyptic number.

It is an amenable number.

21002121353305 is a deficient number, since it is larger than the sum of its proper divisors (4736857089959).

21002121353305 is a wasteful number, since it uses less digits than its factorization.

21002121353305 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 723816.

The product of its (nonzero) digits is 5400, while the sum is 28.

Adding to 21002121353305 its reverse (50335312120012), we get a palindrome (71337433473317).

The spelling of 21002121353305 in words is "twenty-one trillion, two billion, one hundred twenty-one million, three hundred fifty-three thousand, three hundred five".