21601443 has 4 divisors (see below), whose sum is σ = 28801928. Its totient is φ = 14400960.

The previous prime is 21601429. The next prime is 21601453. The reversal of 21601443 is 34410612.

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

It is not a de Polignac number, because 21601443 - 2⁴ = 21601427 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21601453) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3600238 + ... + 3600243.

It is an arithmetic number, because the mean of its divisors is an integer number (7200482).

Almost surely, 2^21601443 is an apocalyptic number.

21601443 is a deficient number, since it is larger than the sum of its proper divisors (7200485).

21601443 is an equidigital number, since it uses as much as digits as its factorization.

21601443 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7200484.

The product of its (nonzero) digits is 576, while the sum is 21.

The square root of 21601443 is about 4647.7352549387. The cubic root of 21601443 is about 278.5015315571.

The spelling of 21601443 in words is "twenty-one million, six hundred one thousand, four hundred forty-three".