21121143552 has 72 divisors (see below), whose sum is σ = 62458957680. Its totient is φ = 7040378880.

The previous prime is 21121143517. The next prime is 21121143557. The reversal of 21121143552 is 25534112112.

It is a happy number.

21121143552 is a `hidden beast` number, since 2 + 11 + 211 + 435 + 5 + 2 = 666.

It is a tau number, because it is divible by the number of its divisors (72).

It is a super-2 number, since 2×21121143552² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (21121143557) 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, 1520949 + ... + 1534772.

Almost surely, 2^21121143552 is an apocalyptic number.

It is an amenable number.

21121143552 is an abundant number, since it is smaller than the sum of its proper divisors (41337814128).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21121143552 is an equidigital number, since it uses as much as digits as its factorization.

21121143552 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3055746 (or 3055726 counting only the distinct ones).

The product of its digits is 2400, while the sum is 27.

Adding to 21121143552 its reverse (25534112112), we get a palindrome (46655255664).

The spelling of 21121143552 in words is "twenty-one billion, one hundred twenty-one million, one hundred forty-three thousand, five hundred fifty-two".