21121443253 has 8 divisors (see below), whose sum is σ = 21176936000. Its totient is φ = 21065984928.

The previous prime is 21121443227. The next prime is 21121443293. The reversal of 21121443253 is 35234412112.

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 21121443253 - 2²⁵ = 21087888821 is a prime.

It is a super-2 number, since 2×21121443253² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21121443293) 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, 1605898 + ... + 1618996.

It is an arithmetic number, because the mean of its divisors is an integer number (2647117000).

Almost surely, 2^21121443253 is an apocalyptic number.

It is an amenable number.

21121443253 is a deficient number, since it is larger than the sum of its proper divisors (55492747).

21121443253 is a wasteful number, since it uses less digits than its factorization.

21121443253 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17211.

The product of its digits is 5760, while the sum is 28.

Adding to 21121443253 its reverse (35234412112), we get a palindrome (56355855365).

The spelling of 21121443253 in words is "twenty-one billion, one hundred twenty-one million, four hundred forty-three thousand, two hundred fifty-three".