21596990 has 16 divisors (see below), whose sum is σ = 39048480. Its totient is φ = 8600160.

The previous prime is 21596983. The next prime is 21597001. The reversal of 21596990 is 9969512.

It is a congruent 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 7 ways as a sum of consecutive naturals, for example, 2426 + ... + 7005.

It is an arithmetic number, because the mean of its divisors is an integer number (2440530).

Almost surely, 2^21596990 is an apocalyptic number.

21596990 is a deficient number, since it is larger than the sum of its proper divisors (17451490).

21596990 is a wasteful number, since it uses less digits than its factorization.

21596990 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9667.

The product of its (nonzero) digits is 43740, while the sum is 41.

The square root of 21596990 is about 4647.2561797258. The cubic root of 21596990 is about 278.4823931358.

The spelling of 21596990 in words is "twenty-one million, five hundred ninety-six thousand, nine hundred ninety".