21121423252 has 24 divisors (see below), whose sum is σ = 37607884160. Its totient is φ = 10377581760.

The previous prime is 21121423243. The next prime is 21121423259. The reversal of 21121423252 is 25232412112.

It is a super-2 number, since 2×21121423252² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21121423259) 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, 91713 + ... + 225064.

Almost surely, 2^21121423252 is an apocalyptic number.

It is an amenable number.

21121423252 is a deficient number, since it is larger than the sum of its proper divisors (16486460908).

21121423252 is a wasteful number, since it uses less digits than its factorization.

21121423252 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 317071 (or 317069 counting only the distinct ones).

The product of its digits is 1920, while the sum is 25.

Adding to 21121423252 its reverse (25232412112), we get a palindrome (46353835364).

The spelling of 21121423252 in words is "twenty-one billion, one hundred twenty-one million, four hundred twenty-three thousand, two hundred fifty-two".