21121233131 has 12 divisors (see below), whose sum is σ = 23010473664. Its totient is φ = 19364108400.

The previous prime is 21121233101. The next prime is 21121233151. The reversal of 21121233131 is 13133212112.

It is a happy number.

It is not a de Polignac number, because 21121233131 - 2³⁰ = 20047491307 is a prime.

It is a super-2 number, since 2×21121233131² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21121233101) 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, 932480 + ... + 954861.

It is an arithmetic number, because the mean of its divisors is an integer number (1917539472).

Almost surely, 2^21121233131 is an apocalyptic number.

21121233131 is a deficient number, since it is larger than the sum of its proper divisors (1889240533).

21121233131 is a wasteful number, since it uses less digits than its factorization.

21121233131 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1887410 (or 1887391 counting only the distinct ones).

The product of its digits is 216, while the sum is 20.

Adding to 21121233131 its reverse (13133212112), we get a palindrome (34254445243).

The spelling of 21121233131 in words is "twenty-one billion, one hundred twenty-one million, two hundred thirty-three thousand, one hundred thirty-one".