21066596 has 6 divisors (see below), whose sum is σ = 36866550. Its totient is φ = 10533296.

The previous prime is 21066593. The next prime is 21066601. The reversal of 21066596 is 69566012.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 17106496 + 3960100 = 4136^2 + 1990^2 .

It is not an unprimeable number, because it can be changed into a prime (21066593) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2633321 + ... + 2633328.

It is an arithmetic number, because the mean of its divisors is an integer number (6144425).

Almost surely, 2^21066596 is an apocalyptic number.

It is an amenable number.

21066596 is a deficient number, since it is larger than the sum of its proper divisors (15799954).

21066596 is a wasteful number, since it uses less digits than its factorization.

21066596 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5266653 (or 5266651 counting only the distinct ones).

The product of its (nonzero) digits is 19440, while the sum is 35.

The square root of 21066596 is about 4589.8361626533. The cubic root of 21066596 is about 276.1837500750.

The spelling of 21066596 in words is "twenty-one million, sixty-six thousand, five hundred ninety-six".