20121311 has 12 divisors (see below), whose sum is σ = 23907168. Its totient is φ = 16877952.

The previous prime is 20121307. The next prime is 20121337. The reversal of 20121311 is 11312102.

It is not a de Polignac number, because 20121311 - 2² = 20121307 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20121292 and 20121301.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20121391) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2066 + ... + 6671.

It is an arithmetic number, because the mean of its divisors is an integer number (1992264).

Almost surely, 2^20121311 is an apocalyptic number.

20121311 is a deficient number, since it is larger than the sum of its proper divisors (3785857).

20121311 is an equidigital number, since it uses as much as digits as its factorization.

20121311 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8798 (or 8791 counting only the distinct ones).

The product of its (nonzero) digits is 12, while the sum is 11.

The square root of 20121311 is about 4485.6784325228. The cubic root of 20121311 is about 271.9894702887.

Adding to 20121311 its reverse (11312102), we get a palindrome (31433413).

It can be divided in two parts, 201 and 21311, that added together give a palindrome (21512).

The spelling of 20121311 in words is "twenty million, one hundred twenty-one thousand, three hundred eleven".