21143001 has 16 divisors (see below), whose sum is σ = 31815360. Its totient is φ = 12371520.

The previous prime is 21142981. The next prime is 21143009. The reversal of 21143001 is 10034112.

It is a happy number.

It is not a de Polignac number, because 21143001 - 2⁵ = 21142969 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21143009) 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, 10090 + ... + 12003.

It is an arithmetic number, because the mean of its divisors is an integer number (1988460).

Almost surely, 2^21143001 is an apocalyptic number.

It is an amenable number.

21143001 is a deficient number, since it is larger than the sum of its proper divisors (10672359).

21143001 is a wasteful number, since it uses less digits than its factorization.

21143001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22136.

The product of its (nonzero) digits is 24, while the sum is 12.

The square root of 21143001 is about 4598.1519113661. The cubic root of 21143001 is about 276.5172378991.

Adding to 21143001 its reverse (10034112), we get a palindrome (31177113).

Subtracting from 21143001 its reverse (10034112), we obtain a square (11108889 = 3333²).

It can be divided in two parts, 2114 and 3001, that added together give a palindrome (5115).

The spelling of 21143001 in words is "twenty-one million, one hundred forty-three thousand, one".