21223078 has 8 divisors (see below), whose sum is σ = 31854168. Its totient is φ = 10605024.

The previous prime is 21223073. The next prime is 21223091. The reversal of 21223078 is 87032212.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21223073) 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, 4750 + ... + 8062.

It is an arithmetic number, because the mean of its divisors is an integer number (3981771).

Almost surely, 2^21223078 is an apocalyptic number.

21223078 is a deficient number, since it is larger than the sum of its proper divisors (10631090).

21223078 is a wasteful number, since it uses less digits than its factorization.

21223078 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6518.

The product of its (nonzero) digits is 1344, while the sum is 25.

The square root of 21223078 is about 4606.8512022856. The cubic root of 21223078 is about 276.8658918918.

The spelling of 21223078 in words is "twenty-one million, two hundred twenty-three thousand, seventy-eight".