21152253305 has 8 divisors (see below), whose sum is σ = 26257969800. Its totient is φ = 16338292096.

The previous prime is 21152253271. The next prime is 21152253313. The reversal of 21152253305 is 50335225112.

It can be written as a sum of positive squares in 4 ways, for example, as 1530687376 + 19621565929 = 39124^2 + 140077^2 .

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 21152253305 - 2¹⁰ = 21152252281 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (29).

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 72938660 + ... + 72938949.

It is an arithmetic number, because the mean of its divisors is an integer number (3282246225).

Almost surely, 2^21152253305 is an apocalyptic number.

It is an amenable number.

21152253305 is a deficient number, since it is larger than the sum of its proper divisors (5105716495).

21152253305 is a wasteful number, since it uses less digits than its factorization.

21152253305 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 145877643.

The product of its (nonzero) digits is 9000, while the sum is 29.

Adding to 21152253305 its reverse (50335225112), we get a palindrome (71487478417).

The spelling of 21152253305 in words is "twenty-one billion, one hundred fifty-two million, two hundred fifty-three thousand, three hundred five".