21773139 has 8 divisors (see below), whose sum is σ = 29153280. Its totient is φ = 14454216.

The previous prime is 21773137. The next prime is 21773149. The reversal of 21773139 is 93137712.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21773139 - 2¹ = 21773137 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21773137) 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 7 ways as a sum of consecutive naturals, for example, 14467 + ... + 15900.

It is an arithmetic number, because the mean of its divisors is an integer number (3644160).

Almost surely, 2^21773139 is an apocalyptic number.

21773139 is a deficient number, since it is larger than the sum of its proper divisors (7380141).

21773139 is a wasteful number, since it uses less digits than its factorization.

21773139 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30609.

The product of its digits is 7938, while the sum is 33.

The square root of 21773139 is about 4666.1696282926. The cubic root of 21773139 is about 279.2374617908.

It can be divided in two parts, 21773 and 139, that added together give a palindrome (21912).

The spelling of 21773139 in words is "twenty-one million, seven hundred seventy-three thousand, one hundred thirty-nine".