21121121131 has 4 divisors (see below), whose sum is σ = 23041223064. Its totient is φ = 19201019200.

The previous prime is 21121121101. The next prime is 21121121233. The reversal of 21121121131 is 13112112112.

It is a happy number.

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

It is a de Polignac number, because none of the positive numbers 2^k-21121121131 is a prime.

It is a super-2 number, since 2×21121121131² (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 (21121121101) 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, 960050950 + ... + 960050971.

It is an arithmetic number, because the mean of its divisors is an integer number (5760305766).

Almost surely, 2^21121121131 is an apocalyptic number.

21121121131 is a deficient number, since it is larger than the sum of its proper divisors (1920101933).

21121121131 is a wasteful number, since it uses less digits than its factorization.

21121121131 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1920101932.

The product of its digits is 24, while the sum is 16.

Adding to 21121121131 its reverse (13112112112), we get a palindrome (34233233243).

The spelling of 21121121131 in words is "twenty-one billion, one hundred twenty-one million, one hundred twenty-one thousand, one hundred thirty-one".