21617994 has 8 divisors (see below), whose sum is σ = 43236000. Its totient is φ = 7205996.

The previous prime is 21617989. The next prime is 21618007. The reversal of 21617994 is 49971612.

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

21617994 is an admirable 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, 1801494 + ... + 1801505.

It is an arithmetic number, because the mean of its divisors is an integer number (5404500).

Almost surely, 2^21617994 is an apocalyptic number.

21617994 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

21617994 is a wasteful number, since it uses less digits than its factorization.

21617994 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3603004.

The product of its digits is 27216, while the sum is 39.

The square root of 21617994 is about 4649.5154586258. The cubic root of 21617994 is about 278.5726425795.

The spelling of 21617994 in words is "twenty-one million, six hundred seventeen thousand, nine hundred ninety-four".