21380285 has 8 divisors (see below), whose sum is σ = 25841760. Its totient is φ = 16980624.

The previous prime is 21380273. The next prime is 21380299. The reversal of 21380285 is 58208312.

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

It is a cyclic number.

It is not a de Polignac number, because 21380285 - 2⁴ = 21380269 is a prime.

It is a congruent 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, 14687 + ... + 16076.

It is an arithmetic number, because the mean of its divisors is an integer number (3230220).

Almost surely, 2^21380285 is an apocalyptic number.

It is an amenable number.

21380285 is a deficient number, since it is larger than the sum of its proper divisors (4461475).

21380285 is a wasteful number, since it uses less digits than its factorization.

21380285 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30907.

The product of its (nonzero) digits is 3840, while the sum is 29.

The square root of 21380285 is about 4623.8820270418. The cubic root of 21380285 is about 277.5478260777.

Adding to 21380285 its reverse (58208312), we get a palindrome (79588597).

The spelling of 21380285 in words is "twenty-one million, three hundred eighty thousand, two hundred eighty-five".