21111311234 has 16 divisors (see below), whose sum is σ = 34117553400. Its totient is φ = 9739491840.

The previous prime is 21111311227. The next prime is 21111311239. The reversal of 21111311234 is 43211311112.

It can be written as a sum of positive squares in 4 ways, for example, as 19980670609 + 1130640625 = 141353^2 + 33625^2 .

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21111311239) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 112559 + ... + 234290.

Almost surely, 2^21111311234 is an apocalyptic number.

21111311234 is a deficient number, since it is larger than the sum of its proper divisors (13006242166).

21111311234 is a wasteful number, since it uses less digits than its factorization.

21111311234 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 349205.

The product of its digits is 144, while the sum is 20.

Adding to 21111311234 its reverse (43211311112), we get a palindrome (64322622346).

The spelling of 21111311234 in words is "twenty-one billion, one hundred eleven million, three hundred eleven thousand, two hundred thirty-four".