21723353252 has 24 divisors (see below), whose sum is σ = 38702210400. Its totient is φ = 10665979136.

The previous prime is 21723353209. The next prime is 21723353273. The reversal of 21723353252 is 25235332712.

It is a super-3 number, since 3×21723353252³ (a number of 32 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 169703 + ... + 268785.

It is an arithmetic number, because the mean of its divisors is an integer number (1612592100).

Almost surely, 2^21723353252 is an apocalyptic number.

It is an amenable number.

21723353252 is a deficient number, since it is larger than the sum of its proper divisors (16978857148).

21723353252 is a wasteful number, since it uses less digits than its factorization.

21723353252 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 100075 (or 100073 counting only the distinct ones).

The product of its digits is 75600, while the sum is 35.

Adding to 21723353252 its reverse (25235332712), we get a palindrome (46958685964).

The spelling of 21723353252 in words is "twenty-one billion, seven hundred twenty-three million, three hundred fifty-three thousand, two hundred fifty-two".