21238386 has 16 divisors (see below), whose sum is σ = 45744384. Its totient is φ = 6534864.

The previous prime is 21238363. The next prime is 21238429. The reversal of 21238386 is 68383212.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 136066 + ... + 136221.

It is an arithmetic number, because the mean of its divisors is an integer number (2859024).

Almost surely, 2^21238386 is an apocalyptic number.

21238386 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

21238386 is an abundant number, since it is smaller than the sum of its proper divisors (24505998).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21238386 is a wasteful number, since it uses less digits than its factorization.

21238386 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 272305.

The product of its digits is 13824, while the sum is 33.

The square root of 21238386 is about 4608.5123413093. The cubic root of 21238386 is about 276.9324427863.

The spelling of 21238386 in words is "twenty-one million, two hundred thirty-eight thousand, three hundred eighty-six".