21009164933 has 4 divisors (see below), whose sum is σ = 21497750208. Its totient is φ = 20520579660.

The previous prime is 21009164863. The next prime is 21009164941. The reversal of 21009164933 is 33946190012.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21009164933 - 2⁸ = 21009164677 is a prime.

It is a super-2 number, since 2×21009164933² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21009164233) 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, 244292573 + ... + 244292658.

It is an arithmetic number, because the mean of its divisors is an integer number (5374437552).

Almost surely, 2^21009164933 is an apocalyptic number.

It is an amenable number.

21009164933 is a deficient number, since it is larger than the sum of its proper divisors (488585275).

21009164933 is an equidigital number, since it uses as much as digits as its factorization.

21009164933 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 488585274.

The product of its (nonzero) digits is 34992, while the sum is 38.

The spelling of 21009164933 in words is "twenty-one billion, nine million, one hundred sixty-four thousand, nine hundred thirty-three".