21827798 has 4 divisors (see below), whose sum is σ = 32741700. Its totient is φ = 10913898.

The previous prime is 21827777. The next prime is 21827801. The reversal of 21827798 is 89772812.

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

It is a congruent number.

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 5456948 + ... + 5456951.

It is an arithmetic number, because the mean of its divisors is an integer number (8185425).

Almost surely, 2^21827798 is an apocalyptic number.

21827798 is a deficient number, since it is larger than the sum of its proper divisors (10913902).

21827798 is a wasteful number, since it uses less digits than its factorization.

21827798 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10913901.

The product of its digits is 112896, while the sum is 44.

The square root of 21827798 is about 4672.0229023411. The cubic root of 21827798 is about 279.4709312097.

The spelling of 21827798 in words is "twenty-one million, eight hundred twenty-seven thousand, seven hundred ninety-eight".