21401143 has 4 divisors (see below), whose sum is σ = 21898888. Its totient is φ = 20903400.

The previous prime is 21401137. The next prime is 21401203. The reversal of 21401143 is 34110412.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21401143 - 2⁵ = 21401111 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21401123) 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 3 ways as a sum of consecutive naturals, for example, 248808 + ... + 248893.

It is an arithmetic number, because the mean of its divisors is an integer number (5474722).

Almost surely, 2^21401143 is an apocalyptic number.

21401143 is a deficient number, since it is larger than the sum of its proper divisors (497745).

21401143 is an equidigital number, since it uses as much as digits as its factorization.

21401143 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 497744.

The product of its (nonzero) digits is 96, while the sum is 16.

The square root of 21401143 is about 4626.1369413367. The cubic root of 21401143 is about 277.6380526738.

Adding to 21401143 its reverse (34110412), we get a palindrome (55511555).

The spelling of 21401143 in words is "twenty-one million, four hundred one thousand, one hundred forty-three".