21056051073 has 16 divisors (see below), whose sum is σ = 28507106880. Its totient is φ = 13821377856.

The previous prime is 21056051041. The next prime is 21056051119. The reversal of 21056051073 is 37015065012.

It is not a de Polignac number, because 21056051073 - 2⁵ = 21056051041 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 21056051073.

It is not an unprimeable number, because it can be changed into a prime (21056050073) 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 15 ways as a sum of consecutive naturals, for example, 426223 + ... + 473051.

It is an arithmetic number, because the mean of its divisors is an integer number (1781694180).

Almost surely, 2^21056051073 is an apocalyptic number.

It is an amenable number.

21056051073 is a deficient number, since it is larger than the sum of its proper divisors (7451055807).

21056051073 is a wasteful number, since it uses less digits than its factorization.

21056051073 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 49136.

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

The spelling of 21056051073 in words is "twenty-one billion, fifty-six million, fifty-one thousand, seventy-three".