21121231112 has 64 divisors (see below), whose sum is σ = 41629593600. Its totient is φ = 10037442880.

The previous prime is 21121231099. The next prime is 21121231123. The reversal of 21121231112 is 21113212112.

It is a happy number.

It is a super-2 number, since 2×21121231112² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1835537 + ... + 1847007.

It is an arithmetic number, because the mean of its divisors is an integer number (650462400).

Almost surely, 2^21121231112 is an apocalyptic number.

It is an amenable number.

21121231112 is a deficient number, since it is larger than the sum of its proper divisors (20508362488).

21121231112 is a wasteful number, since it uses less digits than its factorization.

21121231112 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11666 (or 11662 counting only the distinct ones).

The product of its digits is 48, while the sum is 17.

Adding to 21121231112 its reverse (21113212112), we get a palindrome (42234443224).

The spelling of 21121231112 in words is "twenty-one billion, one hundred twenty-one million, two hundred thirty-one thousand, one hundred twelve".