21111123345 has 128 divisors (see below), whose sum is σ = 40683202560. Its totient is φ = 9234984960.

The previous prime is 21111123281. The next prime is 21111123377. The reversal of 21111123345 is 54332111112.

It is not a de Polignac number, because 21111123345 - 2⁶ = 21111123281 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 35964142 + ... + 35964728.

It is an arithmetic number, because the mean of its divisors is an integer number (317837520).

Almost surely, 2^21111123345 is an apocalyptic number.

It is an amenable number.

21111123345 is a deficient number, since it is larger than the sum of its proper divisors (19572079215).

21111123345 is a wasteful number, since it uses less digits than its factorization.

21111123345 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1215.

The product of its digits is 720, while the sum is 24.

Adding to 21111123345 its reverse (54332111112), we get a palindrome (75443234457).

The spelling of 21111123345 in words is "twenty-one billion, one hundred eleven million, one hundred twenty-three thousand, three hundred forty-five".