21084658 has 16 divisors (see below), whose sum is σ = 38271744. Its totient is φ = 8504640.

The previous prime is 21084649. The next prime is 21084673. The reversal of 21084658 is 85648012.

It is a Harshad number since it is a multiple of its sum of digits (34).

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 7 ways as a sum of consecutive naturals, for example, 44058 + ... + 44533.

It is an arithmetic number, because the mean of its divisors is an integer number (2391984).

Almost surely, 2^21084658 is an apocalyptic number.

21084658 is a deficient number, since it is larger than the sum of its proper divisors (17187086).

21084658 is a wasteful number, since it uses less digits than its factorization.

21084658 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 88617.

The product of its (nonzero) digits is 15360, while the sum is 34.

The square root of 21084658 is about 4591.8033494478. The cubic root of 21084658 is about 276.2626586611.

The spelling of 21084658 in words is "twenty-one million, eighty-four thousand, six hundred fifty-eight".