21178796 has 24 divisors (see below), whose sum is σ = 38419920. Its totient is φ = 10208000.

The previous prime is 21178793. The next prime is 21178813. The reversal of 21178796 is 69787112.

It is a Harshad number since it is a multiple of its sum of digits (41).

It is not an unprimeable number, because it can be changed into a prime (21178793) 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, 13871 + ... + 15321.

It is an arithmetic number, because the mean of its divisors is an integer number (1600830).

Almost surely, 2^21178796 is an apocalyptic number.

It is an amenable number.

21178796 is a deficient number, since it is larger than the sum of its proper divisors (17241124).

21178796 is a wasteful number, since it uses less digits than its factorization.

21178796 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1585 (or 1583 counting only the distinct ones).

The product of its digits is 42336, while the sum is 41.

The square root of 21178796 is about 4602.0425899811. The cubic root of 21178796 is about 276.6731973749.

The spelling of 21178796 in words is "twenty-one million, one hundred seventy-eight thousand, seven hundred ninety-six".