21032305453 has 4 divisors (see below), whose sum is σ = 21166269340. Its totient is φ = 20898341568.

The previous prime is 21032305439. The next prime is 21032305507. The reversal of 21032305453 is 35450323012.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 13386027204 + 7646278249 = 115698^2 + 87443^2 .

It is a cyclic number.

It is not a de Polignac number, because 21032305453 - 2²⁹ = 20495434541 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 (21032305753) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 66981708 + ... + 66982021.

It is an arithmetic number, because the mean of its divisors is an integer number (5291567335).

Almost surely, 2^21032305453 is an apocalyptic number.

It is an amenable number.

21032305453 is a deficient number, since it is larger than the sum of its proper divisors (133963887).

21032305453 is a wasteful number, since it uses less digits than its factorization.

21032305453 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 133963886.

The product of its (nonzero) digits is 10800, while the sum is 28.

Adding to 21032305453 its reverse (35450323012), we get a palindrome (56482628465).

The spelling of 21032305453 in words is "twenty-one billion, thirty-two million, three hundred five thousand, four hundred fifty-three".