21676249 has 8 divisors (see below), whose sum is σ = 25377408. Its totient is φ = 18126240.

The previous prime is 21676231. The next prime is 21676261. The reversal of 21676249 is 94267612.

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

It is a cyclic number.

It is not a de Polignac number, because 21676249 - 2⁹ = 21675737 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21676219) 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 7 ways as a sum of consecutive naturals, for example, 37477 + ... + 38050.

It is an arithmetic number, because the mean of its divisors is an integer number (3172176).

Almost surely, 2^21676249 is an apocalyptic number.

It is an amenable number.

21676249 is a deficient number, since it is larger than the sum of its proper divisors (3701159).

21676249 is an equidigital number, since it uses as much as digits as its factorization.

21676249 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 75575.

The product of its digits is 36288, while the sum is 37.

The square root of 21676249 is about 4655.7758751899. The cubic root of 21676249 is about 278.8226456413.

It can be divided in two parts, 216762 and 49, that added together give a triangular number (216811 = T₆₅₈).

The spelling of 21676249 in words is "twenty-one million, six hundred seventy-six thousand, two hundred forty-nine".