21153144253 has 4 divisors (see below), whose sum is σ = 21603211200. Its totient is φ = 20703077308.

The previous prime is 21153144223. The next prime is 21153144263. The reversal of 21153144253 is 35244135112.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21153144253 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 (21153144203) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 225033403 + ... + 225033496.

It is an arithmetic number, because the mean of its divisors is an integer number (5400802800).

Almost surely, 2^21153144253 is an apocalyptic number.

It is an amenable number.

21153144253 is a deficient number, since it is larger than the sum of its proper divisors (450066947).

21153144253 is an equidigital number, since it uses as much as digits as its factorization.

21153144253 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 450066946.

The product of its digits is 14400, while the sum is 31.

Adding to 21153144253 its reverse (35244135112), we get a palindrome (56397279365).

The spelling of 21153144253 in words is "twenty-one billion, one hundred fifty-three million, one hundred forty-four thousand, two hundred fifty-three".