21082665 has 8 divisors (see below), whose sum is σ = 33732288. Its totient is φ = 11244080.

The previous prime is 21082631. The next prime is 21082667. The reversal of 21082665 is 56628012.

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

It is not a de Polignac number, because 21082665 - 2¹¹ = 21080617 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21082667) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 702741 + ... + 702770.

It is an arithmetic number, because the mean of its divisors is an integer number (4216536).

Almost surely, 2^21082665 is an apocalyptic number.

It is an amenable number.

21082665 is a deficient number, since it is larger than the sum of its proper divisors (12649623).

21082665 is a wasteful number, since it uses less digits than its factorization.

21082665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1405519.

The product of its (nonzero) digits is 5760, while the sum is 30.

The square root of 21082665 is about 4591.5863271858. The cubic root of 21082665 is about 276.2539539302.

The spelling of 21082665 in words is "twenty-one million, eighty-two thousand, six hundred sixty-five".