21000311113 has 4 divisors (see below), whose sum is σ = 21006562708. Its totient is φ = 20994059520.

The previous prime is 21000311107. The next prime is 21000311159. The reversal of 21000311113 is 31111300012.

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

It can be written as a sum of positive squares in 2 ways, for example, as 18151633984 + 2848677129 = 134728^2 + 53373^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21000311113 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21000311093 and 21000311102.

It is not an unprimeable number, because it can be changed into a prime (21000311413) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3120756 + ... + 3127477.

It is an arithmetic number, because the mean of its divisors is an integer number (5251640677).

Almost surely, 2^21000311113 is an apocalyptic number.

It is an amenable number.

21000311113 is a deficient number, since it is larger than the sum of its proper divisors (6251595).

21000311113 is an equidigital number, since it uses as much as digits as its factorization.

21000311113 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6251594.

The product of its (nonzero) digits is 18, while the sum is 13.

Adding to 21000311113 its reverse (31111300012), we get a palindrome (52111611125).

The spelling of 21000311113 in words is "twenty-one billion, three hundred eleven thousand, one hundred thirteen".