21243115552 has 24 divisors (see below), whose sum is σ = 43171494912. Its totient is φ = 10278926400.

The previous prime is 21243115541. The next prime is 21243115567. The reversal of 21243115552 is 25551134212.

It is a Harshad number since it is a multiple of its sum of digits (31).

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10706224 + ... + 10708207.

It is an arithmetic number, because the mean of its divisors is an integer number (1798812288).

Almost surely, 2^21243115552 is an apocalyptic number.

It is an amenable number.

21243115552 is an abundant number, since it is smaller than the sum of its proper divisors (21928379360).

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

21243115552 is a wasteful number, since it uses less digits than its factorization.

21243115552 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21414472 (or 21414464 counting only the distinct ones).

The product of its digits is 12000, while the sum is 31.

Adding to 21243115552 its reverse (25551134212), we get a palindrome (46794249764).

The spelling of 21243115552 in words is "twenty-one billion, two hundred forty-three million, one hundred fifteen thousand, five hundred fifty-two".