21045452345 has 8 divisors (see below), whose sum is σ = 26740104264. Its totient is φ = 15845987584.

The previous prime is 21045452327. The next prime is 21045452347. The reversal of 21045452345 is 54325454012.

It can be written as a sum of positive squares in 4 ways, for example, as 1162196281 + 19883256064 = 34091^2 + 141008^2 .

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 21045452345 - 2²⁰ = 21044403769 is a prime.

It is a super-2 number, since 2×21045452345² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21045452347) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 123796694 + ... + 123796863.

It is an arithmetic number, because the mean of its divisors is an integer number (3342513033).

Almost surely, 2^21045452345 is an apocalyptic number.

It is an amenable number.

21045452345 is a deficient number, since it is larger than the sum of its proper divisors (5694651919).

21045452345 is a wasteful number, since it uses less digits than its factorization.

21045452345 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 247593579.

The product of its (nonzero) digits is 96000, while the sum is 35.

The spelling of 21045452345 in words is "twenty-one billion, forty-five million, four hundred fifty-two thousand, three hundred forty-five".