20645966 has 8 divisors (see below), whose sum is σ = 33784344. Its totient is φ = 9384520.

The previous prime is 20645957. The next prime is 20645981. The reversal of 20645966 is 66954602.

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

It is a congruent number.

It is an unprimeable number.

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 in 3 ways as a sum of consecutive naturals, for example, 469205 + ... + 469248.

It is an arithmetic number, because the mean of its divisors is an integer number (4223043).

Almost surely, 2^20645966 is an apocalyptic number.

20645966 is a deficient number, since it is larger than the sum of its proper divisors (13138378).

20645966 is a wasteful number, since it uses less digits than its factorization.

20645966 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 938466.

The product of its (nonzero) digits is 77760, while the sum is 38.

The square root of 20645966 is about 4543.7832254631. The cubic root of 20645966 is about 274.3332209638. Note that the first 3 decimals are identical.

It can be divided in two parts, 2064596 and 6, that added together give a palindrome (2064602).

The spelling of 20645966 in words is "twenty million, six hundred forty-five thousand, nine hundred sixty-six".