21002105311 has 16 divisors (see below), whose sum is σ = 23599963296. Its totient is φ = 18524160000.

The previous prime is 21002105309. The next prime is 21002105321. The reversal of 21002105311 is 11350120012.

It is a cyclic number.

It is not a de Polignac number, because 21002105311 - 2¹ = 21002105309 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21002105321) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 47010 + ... + 210271.

It is an arithmetic number, because the mean of its divisors is an integer number (1474997706).

Almost surely, 2^21002105311 is an apocalyptic number.

21002105311 is a deficient number, since it is larger than the sum of its proper divisors (2597857985).

21002105311 is a wasteful number, since it uses less digits than its factorization.

21002105311 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 257514.

The product of its (nonzero) digits is 60, while the sum is 16.

Adding to 21002105311 its reverse (11350120012), we get a palindrome (32352225323).

The spelling of 21002105311 in words is "twenty-one billion, two million, one hundred five thousand, three hundred eleven".