20121213131 has 4 divisors (see below), whose sum is σ = 20265970200. Its totient is φ = 19976456064.

The previous prime is 20121213109. The next prime is 20121213187. The reversal of 20121213131 is 13131212102.

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

It is a cyclic number.

It is not a de Polignac number, because 20121213131 - 2⁶ = 20121213067 is a prime.

It is a super-2 number, since 2×20121213131² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20121215131) 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, 72378326 + ... + 72378603.

It is an arithmetic number, because the mean of its divisors is an integer number (5066492550).

Almost surely, 2^20121213131 is an apocalyptic number.

20121213131 is a deficient number, since it is larger than the sum of its proper divisors (144757069).

20121213131 is a wasteful number, since it uses less digits than its factorization.

20121213131 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 144757068.

The product of its (nonzero) digits is 72, while the sum is 17.

Adding to 20121213131 its reverse (13131212102), we get a palindrome (33252425233).

The spelling of 20121213131 in words is "twenty billion, one hundred twenty-one million, two hundred thirteen thousand, one hundred thirty-one".