21453012545 has 8 divisors (see below), whose sum is σ = 25761638760. Its totient is φ = 17150394240.

The previous prime is 21453012527. The next prime is 21453012563. The reversal of 21453012545 is 54521035412.

It is an interprime number because it is at equal distance from previous prime (21453012527) and next prime (21453012563).

It can be written as a sum of positive squares in 4 ways, for example, as 2637952321 + 18815060224 = 51361^2 + 137168^2 .

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

It is not a de Polignac number, because 21453012545 - 2⁸ = 21453012289 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1494116 + ... + 1508405.

It is an arithmetic number, because the mean of its divisors is an integer number (3220204845).

Almost surely, 2^21453012545 is an apocalyptic number.

It is an amenable number.

21453012545 is a deficient number, since it is larger than the sum of its proper divisors (4308626215).

21453012545 is a wasteful number, since it uses less digits than its factorization.

21453012545 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3003955.

The product of its (nonzero) digits is 24000, while the sum is 32.

Adding to 21453012545 its reverse (54521035412), we get a palindrome (75974047957).

The spelling of 21453012545 in words is "twenty-one billion, four hundred fifty-three million, twelve thousand, five hundred forty-five".