20121212131 has 4 divisors (see below), whose sum is σ = 20122974664. Its totient is φ = 20119449600.

The previous prime is 20121212117. The next prime is 20121212171. The reversal of 20121212131 is 13121212102.

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 20121212131 - 2⁵ = 20121212099 is a prime.

It is a super-2 number, since 2×20121212131² (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 (20121212171) 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, 864030 + ... + 887011.

It is an arithmetic number, because the mean of its divisors is an integer number (5030743666).

Almost surely, 2^20121212131 is an apocalyptic number.

20121212131 is a deficient number, since it is larger than the sum of its proper divisors (1762533).

20121212131 is a wasteful number, since it uses less digits than its factorization.

20121212131 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1762532.

The product of its (nonzero) digits is 48, while the sum is 16.

Adding to 20121212131 its reverse (13121212102), we get a palindrome (33242424233).

The spelling of 20121212131 in words is "twenty billion, one hundred twenty-one million, two hundred twelve thousand, one hundred thirty-one".