21164660073 has 8 divisors (see below), whose sum is σ = 31355052000. Its totient is φ = 14109773364.

The previous prime is 21164660029. The next prime is 21164660087. The reversal of 21164660073 is 37006646112.

It is a happy number.

21164660073 is a `hidden beast` number, since 2 + 1 + 1 + 6 + 46 + 600 + 7 + 3 = 666.

It is not a de Polignac number, because 21164660073 - 2⁹ = 21164659561 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21164660003) 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 7 ways as a sum of consecutive naturals, for example, 391938123 + ... + 391938176.

It is an arithmetic number, because the mean of its divisors is an integer number (3919381500).

Almost surely, 2^21164660073 is an apocalyptic number.

It is an amenable number.

21164660073 is a deficient number, since it is larger than the sum of its proper divisors (10190391927).

21164660073 is an equidigital number, since it uses as much as digits as its factorization.

21164660073 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 783876308 (or 783876302 counting only the distinct ones).

The product of its (nonzero) digits is 36288, while the sum is 36.

The spelling of 21164660073 in words is "twenty-one billion, one hundred sixty-four million, six hundred sixty thousand, seventy-three".