21311312101 has 4 divisors (see below), whose sum is σ = 22237890912. Its totient is φ = 20384733292.

The previous prime is 21311312083. The next prime is 21311312107. The reversal of 21311312101 is 10121311312.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21311312101 - 2¹⁷ = 21311181029 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 (21311312107) 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, 463289371 + ... + 463289416.

It is an arithmetic number, because the mean of its divisors is an integer number (5559472728).

Almost surely, 2^21311312101 is an apocalyptic number.

It is an amenable number.

21311312101 is a deficient number, since it is larger than the sum of its proper divisors (926578811).

21311312101 is an equidigital number, since it uses as much as digits as its factorization.

21311312101 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 926578810.

The product of its (nonzero) digits is 36, while the sum is 16.

Adding to 21311312101 its reverse (10121311312), we get a palindrome (31432623413).

It can be divided in two parts, 21311312 and 101, that multiplied together give a palindrome (2152442512).

The spelling of 21311312101 in words is "twenty-one billion, three hundred eleven million, three hundred twelve thousand, one hundred one".