21166617952 has 24 divisors (see below), whose sum is σ = 42140007000. Its totient is φ = 10464393984.

The previous prime is 21166617889. The next prime is 21166617959. The reversal of 21166617952 is 25971666112.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21166617959) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3713202 + ... + 3718897.

It is an arithmetic number, because the mean of its divisors is an integer number (1755833625).

Almost surely, 2^21166617952 is an apocalyptic number.

It is an amenable number.

21166617952 is a deficient number, since it is larger than the sum of its proper divisors (20973389048).

21166617952 is an equidigital number, since it uses as much as digits as its factorization.

21166617952 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7432198 (or 7432190 counting only the distinct ones).

The product of its digits is 272160, while the sum is 46.

The spelling of 21166617952 in words is "twenty-one billion, one hundred sixty-six million, six hundred seventeen thousand, nine hundred fifty-two".