21001573065 has 16 divisors (see below), whose sum is σ = 36657291456. Its totient is φ = 10182580800.

The previous prime is 21001573039. The next prime is 21001573091. The reversal of 21001573065 is 56037510012.

It is an interprime number because it is at equal distance from previous prime (21001573039) and next prime (21001573091).

It is not a de Polignac number, because 21001573065 - 2¹⁰ = 21001572041 is a prime.

It is a Curzon number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 63640966 + ... + 63641295.

It is an arithmetic number, because the mean of its divisors is an integer number (2291080716).

Almost surely, 2^21001573065 is an apocalyptic number.

It is an amenable number.

21001573065 is a deficient number, since it is larger than the sum of its proper divisors (15655718391).

21001573065 is a wasteful number, since it uses less digits than its factorization.

21001573065 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 127282280.

The product of its (nonzero) digits is 6300, while the sum is 30.

The spelling of 21001573065 in words is "twenty-one billion, one million, five hundred seventy-three thousand, sixty-five".