21010021311 has 4 divisors (see below), whose sum is σ = 28013361752. Its totient is φ = 14006680872.

The previous prime is 21010021271. The next prime is 21010021327. The reversal of 21010021311 is 11312001012.

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

It is not a de Polignac number, because 21010021311 - 2⁶ = 21010021247 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 (21010021391) 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, 3501670216 + ... + 3501670221.

It is an arithmetic number, because the mean of its divisors is an integer number (7003340438).

Almost surely, 2^21010021311 is an apocalyptic number.

21010021311 is a deficient number, since it is larger than the sum of its proper divisors (7003340441).

21010021311 is an equidigital number, since it uses as much as digits as its factorization.

21010021311 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7003340440.

The product of its (nonzero) digits is 12, while the sum is 12.

Adding to 21010021311 its reverse (11312001012), we get a palindrome (32322022323).

The spelling of 21010021311 in words is "twenty-one billion, ten million, twenty-one thousand, three hundred eleven".