21123232005 has 16 divisors (see below), whose sum is σ = 33799633920. Its totient is φ = 11264902848.

The previous prime is 21123231953. The next prime is 21123232049. The reversal of 21123232005 is 50023232112.

It is not a de Polignac number, because 21123232005 - 2⁸ = 21123231749 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 201639 + ... + 287931.

It is an arithmetic number, because the mean of its divisors is an integer number (2112477120).

Almost surely, 2^21123232005 is an apocalyptic number.

It is an amenable number.

21123232005 is a deficient number, since it is larger than the sum of its proper divisors (12676401915).

21123232005 is a wasteful number, since it uses less digits than its factorization.

21123232005 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 102620.

The product of its (nonzero) digits is 720, while the sum is 21.

Adding to 21123232005 its reverse (50023232112), we get a palindrome (71146464117).

The spelling of 21123232005 in words is "twenty-one billion, one hundred twenty-three million, two hundred thirty-two thousand, five".