21121031223 has 24 divisors (see below), whose sum is σ = 31692469536. Its totient is φ = 13543756800.

The previous prime is 21121031189. The next prime is 21121031231. The reversal of 21121031223 is 32213012112.

It is not a de Polignac number, because 21121031223 - 2¹⁸ = 21120769079 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21121031196 and 21121031205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21121031233) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 376890 + ... + 429287.

It is an arithmetic number, because the mean of its divisors is an integer number (1320519564).

Almost surely, 2^21121031223 is an apocalyptic number.

21121031223 is a deficient number, since it is larger than the sum of its proper divisors (10571438313).

21121031223 is a wasteful number, since it uses less digits than its factorization.

21121031223 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 806295 (or 806292 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

Adding to 21121031223 its reverse (32213012112), we get a palindrome (53334043335).

The spelling of 21121031223 in words is "twenty-one billion, one hundred twenty-one million, thirty-one thousand, two hundred twenty-three".