21320453253 has 24 divisors (see below), whose sum is σ = 33084543744. Its totient is φ = 12161395840.

The previous prime is 21320453249. The next prime is 21320453263. The reversal of 21320453253 is 35235402312.

It is not a de Polignac number, because 21320453253 - 2² = 21320453249 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21320453253.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21320453263) 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 23 ways as a sum of consecutive naturals, for example, 1721301 + ... + 1733642.

It is an arithmetic number, because the mean of its divisors is an integer number (1378522656).

Almost surely, 2^21320453253 is an apocalyptic number.

It is an amenable number.

21320453253 is a deficient number, since it is larger than the sum of its proper divisors (11764090491).

21320453253 is a wasteful number, since it uses less digits than its factorization.

21320453253 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3454985 (or 3454974 counting only the distinct ones).

The product of its (nonzero) digits is 21600, while the sum is 30.

Adding to 21320453253 its reverse (35235402312), we get a palindrome (56555855565).

The spelling of 21320453253 in words is "twenty-one billion, three hundred twenty million, four hundred fifty-three thousand, two hundred fifty-three".