21003324123 has 16 divisors (see below), whose sum is σ = 28274428160. Its totient is φ = 13867337376.

The previous prime is 21003324107. The next prime is 21003324127. The reversal of 21003324123 is 32142330012.

It is not a de Polignac number, because 21003324123 - 2⁴ = 21003324107 is a prime.

It is a super-2 number, since 2×21003324123² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21003324123.

It is not an unprimeable number, because it can be changed into a prime (21003324127) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 753786 + ... + 781152.

It is an arithmetic number, because the mean of its divisors is an integer number (1767151760).

Almost surely, 2^21003324123 is an apocalyptic number.

21003324123 is a deficient number, since it is larger than the sum of its proper divisors (7271104037).

21003324123 is a wasteful number, since it uses less digits than its factorization.

21003324123 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29826.

The product of its (nonzero) digits is 864, while the sum is 21.

Adding to 21003324123 its reverse (32142330012), we get a palindrome (53145654135).

The spelling of 21003324123 in words is "twenty-one billion, three million, three hundred twenty-four thousand, one hundred twenty-three".