21111065554 has 16 divisors (see below), whose sum is σ = 31730683392. Its totient is φ = 10534191808.

The previous prime is 21111065539. The next prime is 21111065669. The reversal of 21111065554 is 45556011112.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2705082 + ... + 2712874.

It is an arithmetic number, because the mean of its divisors is an integer number (1983167712).

Almost surely, 2^21111065554 is an apocalyptic number.

21111065554 is a deficient number, since it is larger than the sum of its proper divisors (10619617838).

21111065554 is a wasteful number, since it uses less digits than its factorization.

21111065554 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10361.

The product of its (nonzero) digits is 6000, while the sum is 31.

Adding to 21111065554 its reverse (45556011112), we get a palindrome (66667076666).

The spelling of 21111065554 in words is "twenty-one billion, one hundred eleven million, sixty-five thousand, five hundred fifty-four".