21111211424 has 24 divisors (see below), whose sum is σ = 41568391620. Its totient is φ = 10554159616.

The previous prime is 21111211409. The next prime is 21111211453. The reversal of 21111211424 is 42411211112.

It can be written as a sum of positive squares in 2 ways, for example, as 16946832400 + 4164379024 = 130180^2 + 64532^2 .

It is a nude number because it is divisible by every one of its digits.

It is a junction number, because it is equal to n+sod(n) for n = 21111211396 and 21111211405.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 215102 + ... + 297474.

Almost surely, 2^21111211424 is an apocalyptic number.

It is an amenable number.

21111211424 is a deficient number, since it is larger than the sum of its proper divisors (20457180196).

21111211424 is an equidigital number, since it uses as much as digits as its factorization.

21111211424 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 90392 (or 90384 counting only the distinct ones).

The product of its digits is 128, while the sum is 20.

Adding to 21111211424 its reverse (42411211112), we get a palindrome (63522422536).

The spelling of 21111211424 in words is "twenty-one billion, one hundred eleven million, two hundred eleven thousand, four hundred twenty-four".