21702238 has 8 divisors (see below), whose sum is σ = 33039432. Its totient is φ = 10689096.

The previous prime is 21702221. The next prime is 21702253. The reversal of 21702238 is 83220712.

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, 80845 + ... + 81112.

It is an arithmetic number, because the mean of its divisors is an integer number (4129929).

Almost surely, 2^21702238 is an apocalyptic number.

21702238 is a deficient number, since it is larger than the sum of its proper divisors (11337194).

21702238 is a wasteful number, since it uses less digits than its factorization.

21702238 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 162026.

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

The square root of 21702238 is about 4658.5660884010. The cubic root of 21702238 is about 278.9340337270.

The spelling of 21702238 in words is "twenty-one million, seven hundred two thousand, two hundred thirty-eight".