21125132005 has 16 divisors (see below), whose sum is σ = 25435448064. Its totient is φ = 16843337280.

The previous prime is 21125132003. The next prime is 21125132033. The reversal of 21125132005 is 50023152112.

It is not a de Polignac number, because 21125132005 - 2¹ = 21125132003 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21125132003) 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, 2094675 + ... + 2104735.

It is an arithmetic number, because the mean of its divisors is an integer number (1589715504).

Almost surely, 2^21125132005 is an apocalyptic number.

It is an amenable number.

21125132005 is a deficient number, since it is larger than the sum of its proper divisors (4310316059).

21125132005 is a wasteful number, since it uses less digits than its factorization.

21125132005 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11436.

The product of its (nonzero) digits is 600, while the sum is 22.

Adding to 21125132005 its reverse (50023152112), we get a palindrome (71148284117).

The spelling of 21125132005 in words is "twenty-one billion, one hundred twenty-five million, one hundred thirty-two thousand, five".