21111021123 has 8 divisors (see below), whose sum is σ = 28362899136. Its totient is φ = 13966578600.

The previous prime is 21111021101. The next prime is 21111021131. The reversal of 21111021123 is 32112011112.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21111021123 - 2⁶ = 21111021059 is a prime.

It is a super-2 number, since 2×21111021123² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21111021133) 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, 26858413 + ... + 26859198.

It is an arithmetic number, because the mean of its divisors is an integer number (3545362392).

Almost surely, 2^21111021123 is an apocalyptic number.

21111021123 is a deficient number, since it is larger than the sum of its proper divisors (7251878013).

21111021123 is a wasteful number, since it uses less digits than its factorization.

21111021123 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53717745.

The product of its (nonzero) digits is 24, while the sum is 15.

Adding to 21111021123 its reverse (32112011112), we get a palindrome (53223032235).

The spelling of 21111021123 in words is "twenty-one billion, one hundred eleven million, twenty-one thousand, one hundred twenty-three".