21305523353 has 8 divisors (see below), whose sum is σ = 21657943560. Its totient is φ = 20955957120.

The previous prime is 21305523307. The next prime is 21305523361. The reversal of 21305523353 is 35332550312.

It can be written as a sum of positive squares in 4 ways, for example, as 6752237584 + 14553285769 = 82172^2 + 120637^2 .

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 21305523353 - 2⁸ = 21305523097 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21305523653) 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, 698438 + ... + 728303.

It is an arithmetic number, because the mean of its divisors is an integer number (2707242945).

Almost surely, 2^21305523353 is an apocalyptic number.

It is an amenable number.

21305523353 is a deficient number, since it is larger than the sum of its proper divisors (352420207).

21305523353 is a wasteful number, since it uses less digits than its factorization.

21305523353 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1426987.

The product of its (nonzero) digits is 40500, while the sum is 32.

The spelling of 21305523353 in words is "twenty-one billion, three hundred five million, five hundred twenty-three thousand, three hundred fifty-three".