21278422 has 8 divisors (see below), whose sum is σ = 34819272. Its totient is φ = 9672000.

The previous prime is 21278419. The next prime is 21278449. The reversal of 21278422 is 22487212.

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

It is a congruent number.

It is an unprimeable number.

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, 483579 + ... + 483622.

It is an arithmetic number, because the mean of its divisors is an integer number (4352409).

Almost surely, 2^21278422 is an apocalyptic number.

21278422 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

21278422 is a deficient number, since it is larger than the sum of its proper divisors (13540850).

21278422 is a wasteful number, since it uses less digits than its factorization.

21278422 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 967214.

The product of its digits is 3584, while the sum is 28.

The square root of 21278422 is about 4612.8539972559. The cubic root of 21278422 is about 277.1063465814.

The spelling of 21278422 in words is "twenty-one million, two hundred seventy-eight thousand, four hundred twenty-two".