21841378 has 8 divisors (see below), whose sum is σ = 35282268. Its totient is φ = 10080624.

The previous prime is 21841373. The next prime is 21841399. The reversal of 21841378 is 87314812.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 21650409 + 190969 = 4653^2 + 437^2 .

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 (21841373) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 420001 + ... + 420052.

Almost surely, 2^21841378 is an apocalyptic number.

21841378 is a deficient number, since it is larger than the sum of its proper divisors (13440890).

21841378 is a wasteful number, since it uses less digits than its factorization.

21841378 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 840068.

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

The square root of 21841378 is about 4673.4760082833. The cubic root of 21841378 is about 279.5288761058.

The spelling of 21841378 in words is "twenty-one million, eight hundred forty-one thousand, three hundred seventy-eight".