21121121110 has 32 divisors (see below), whose sum is σ = 38285913600. Its totient is φ = 8389054560.

The previous prime is 21121121101. The next prime is 21121121233. The reversal of 21121121110 is 1112112112.

It is a happy number.

It is a super-2 number, since 2×21121121110² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

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, 1278805 + ... + 1295215.

It is an arithmetic number, because the mean of its divisors is an integer number (1196434800).

Almost surely, 2^21121121110 is an apocalyptic number.

21121121110 is a deficient number, since it is larger than the sum of its proper divisors (17164792490).

21121121110 is a wasteful number, since it uses less digits than its factorization.

21121121110 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17316.

The product of its (nonzero) digits is 8, while the sum is 13.

Adding to 21121121110 its reverse (1112112112), we get a palindrome (22233233222).

The spelling of 21121121110 in words is "twenty-one billion, one hundred twenty-one million, one hundred twenty-one thousand, one hundred ten".