21073143 has 16 divisors (see below), whose sum is σ = 34582016. Its totient is φ = 11115360.

The previous prime is 21073141. The next prime is 21073159. The reversal of 21073143 is 34137012.

It is not a de Polignac number, because 21073143 - 2¹ = 21073141 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21073141) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 38323 + ... + 38868.

It is an arithmetic number, because the mean of its divisors is an integer number (2161376).

Almost surely, 2^21073143 is an apocalyptic number.

21073143 is a deficient number, since it is larger than the sum of its proper divisors (13508873).

21073143 is a wasteful number, since it uses less digits than its factorization.

21073143 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 77214.

The product of its (nonzero) digits is 504, while the sum is 21.

The square root of 21073143 is about 4590.5493135354. The cubic root of 21073143 is about 276.2123575717.

The spelling of 21073143 in words is "twenty-one million, seventy-three thousand, one hundred forty-three".