27821409 has 24 divisors (see below), whose sum is σ = 46603200. Its totient is φ = 14451360.

The previous prime is 27821393. The next prime is 27821413. The reversal of 27821409 is 90412872.

It is a happy number.

It is not a de Polignac number, because 27821409 - 2⁴ = 27821393 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a self number, because there is not a number n which added to its sum of digits gives 27821409.

It is not an unprimeable number, because it can be changed into a prime (27821459) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2934 + ... + 8015.

It is an arithmetic number, because the mean of its divisors is an integer number (1941800).

Almost surely, 2^27821409 is an apocalyptic number.

It is an amenable number.

27821409 is a deficient number, since it is larger than the sum of its proper divisors (18781791).

27821409 is a wasteful number, since it uses less digits than its factorization.

27821409 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10981 (or 10970 counting only the distinct ones).

The product of its (nonzero) digits is 8064, while the sum is 33.

The square root of 27821409 is about 5274.6003640086. The cubic root of 27821409 is about 303.0119155745.

The spelling of 27821409 in words is "twenty-seven million, eight hundred twenty-one thousand, four hundred nine".