21379143 has 4 divisors (see below), whose sum is σ = 28505528. Its totient is φ = 14252760.

The previous prime is 21379129. The next prime is 21379157. The reversal of 21379143 is 34197312.

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

It is an interprime number because it is at equal distance from previous prime (21379129) and next prime (21379157).

It is not a de Polignac number, because 21379143 - 2²⁰ = 20330567 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21379143.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21379103) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3563188 + ... + 3563193.

It is an arithmetic number, because the mean of its divisors is an integer number (7126382).

Almost surely, 2^21379143 is an apocalyptic number.

21379143 is a deficient number, since it is larger than the sum of its proper divisors (7126385).

21379143 is an equidigital number, since it uses as much as digits as its factorization.

21379143 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7126384.

The product of its digits is 4536, while the sum is 30.

The square root of 21379143 is about 4623.7585360830. The cubic root of 21379143 is about 277.5428843715.

The spelling of 21379143 in words is "twenty-one million, three hundred seventy-nine thousand, one hundred forty-three".