21077443 has 4 divisors (see below), whose sum is σ = 21087688. Its totient is φ = 21067200.

The previous prime is 21077431. The next prime is 21077447. The reversal of 21077443 is 34477012.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 21077443 - 2¹⁷ = 20946371 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21077447) 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, 846 + ... + 6547.

It is an arithmetic number, because the mean of its divisors is an integer number (5271922).

Almost surely, 2^21077443 is an apocalyptic number.

21077443 is a deficient number, since it is larger than the sum of its proper divisors (10245).

21077443 is an equidigital number, since it uses as much as digits as its factorization.

21077443 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10244.

The product of its (nonzero) digits is 4704, while the sum is 28.

The square root of 21077443 is about 4591.0176431811. The cubic root of 21077443 is about 276.2311434479.

The spelling of 21077443 in words is "twenty-one million, seventy-seven thousand, four hundred forty-three".