21121131244 has 12 divisors (see below), whose sum is σ = 36981134568. Its totient is φ = 10555092800.

The previous prime is 21121131223. The next prime is 21121131247. The reversal of 21121131244 is 44213112112.

It is a super-2 number, since 2×21121131244² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21121131247) 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, 1359517 + ... + 1374964.

It is an arithmetic number, because the mean of its divisors is an integer number (3081761214).

Almost surely, 2^21121131244 is an apocalyptic number.

It is an amenable number.

21121131244 is a deficient number, since it is larger than the sum of its proper divisors (15860003324).

21121131244 is a wasteful number, since it uses less digits than its factorization.

21121131244 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2736416 (or 2736414 counting only the distinct ones).

The product of its digits is 384, while the sum is 22.

Adding to 21121131244 its reverse (44213112112), we get a palindrome (65334243356).

The spelling of 21121131244 in words is "twenty-one billion, one hundred twenty-one million, one hundred thirty-one thousand, two hundred forty-four".