21232431005 has 8 divisors (see below), whose sum is σ = 25712669400. Its totient is φ = 16830110016.

The previous prime is 21232431001. The next prime is 21232431037. The reversal of 21232431005 is 50013423212.

It can be written as a sum of positive squares in 4 ways, for example, as 4311104281 + 16921326724 = 65659^2 + 130082^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 21232431005 - 2² = 21232431001 is a prime.

It is a super-2 number, since 2×21232431005² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21232431001) 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, 19478750 + ... + 19479839.

It is an arithmetic number, because the mean of its divisors is an integer number (3214083675).

Almost surely, 2^21232431005 is an apocalyptic number.

It is an amenable number.

21232431005 is a deficient number, since it is larger than the sum of its proper divisors (4480238395).

21232431005 is a wasteful number, since it uses less digits than its factorization.

21232431005 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38958703.

The product of its (nonzero) digits is 1440, while the sum is 23.

Adding to 21232431005 its reverse (50013423212), we get a palindrome (71245854217).

The spelling of 21232431005 in words is "twenty-one billion, two hundred thirty-two million, four hundred thirty-one thousand, five".