21579143 has 2 divisors, whose sum is σ = 21579144. Its totient is φ = 21579142.

The previous prime is 21579127. The next prime is 21579167. The reversal of 21579143 is 34197512.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21579143 - 2⁴ = 21579127 is a prime.

It is a super-2 number, since 2×21579143² = 931318825228898, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21579113) 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 as a sum of consecutive naturals, namely, 10789571 + 10789572.

It is an arithmetic number, because the mean of its divisors is an integer number (10789572).

Almost surely, 2^21579143 is an apocalyptic number.

21579143 is a deficient number, since it is larger than the sum of its proper divisors (1).

21579143 is an equidigital number, since it uses as much as digits as its factorization.

21579143 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 7560, while the sum is 32.

The square root of 21579143 is about 4645.3356175846. The cubic root of 21579143 is about 278.4056626141.

The spelling of 21579143 in words is "twenty-one million, five hundred seventy-nine thousand, one hundred forty-three".