20021212131 has 4 divisors (see below), whose sum is σ = 26694949512. Its totient is φ = 13347474752.

The previous prime is 20021212111. The next prime is 20021212157. The reversal of 20021212131 is 13121212002.

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 20021212131 - 2⁹ = 20021211619 is a prime.

It is a super-2 number, since 2×20021212131² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 20021212131.

It is not an unprimeable number, because it can be changed into a prime (20021212111) 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, 3336868686 + ... + 3336868691.

It is an arithmetic number, because the mean of its divisors is an integer number (6673737378).

Almost surely, 2^20021212131 is an apocalyptic number.

20021212131 is a deficient number, since it is larger than the sum of its proper divisors (6673737381).

20021212131 is an equidigital number, since it uses as much as digits as its factorization.

20021212131 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6673737380.

The product of its (nonzero) digits is 48, while the sum is 15.

Adding to 20021212131 its reverse (13121212002), we get a palindrome (33142424133).

The spelling of 20021212131 in words is "twenty billion, twenty-one million, two hundred twelve thousand, one hundred thirty-one".