21814378 has 8 divisors (see below), whose sum is σ = 33519780. Its totient is φ = 10641120.

The previous prime is 21814369. The next prime is 21814379. The reversal of 21814378 is 87341812.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 21780889 + 33489 = 4667^2 + 183^2 .

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

It is not an unprimeable number, because it can be changed into a prime (21814379) 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 3 ways as a sum of consecutive naturals, for example, 132933 + ... + 133096.

Almost surely, 2^21814378 is an apocalyptic number.

21814378 is a deficient number, since it is larger than the sum of its proper divisors (11705402).

21814378 is a wasteful number, since it uses less digits than its factorization.

21814378 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 266072.

The product of its digits is 10752, while the sum is 34.

The square root of 21814378 is about 4670.5864728105. The cubic root of 21814378 is about 279.4136454071.

The spelling of 21814378 in words is "twenty-one million, eight hundred fourteen thousand, three hundred seventy-eight".