20730664 has 8 divisors (see below), whose sum is σ = 38870010. Its totient is φ = 10365328.

The previous prime is 20730623. The next prime is 20730719. The reversal of 20730664 is 46603702.

It can be written as a sum of positive squares in only one way, i.e., 20520900 + 209764 = 4530^2 + 458^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is a hoax number, since the sum of its digits (28) coincides with the sum of the digits of its distinct prime factors.

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 as a sum of consecutive naturals, namely, 1295659 + ... + 1295674.

Almost surely, 2^20730664 is an apocalyptic number.

It is an amenable number.

20730664 is a deficient number, since it is larger than the sum of its proper divisors (18139346).

20730664 is a wasteful number, since it uses less digits than its factorization.

20730664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2591339 (or 2591335 counting only the distinct ones).

The product of its (nonzero) digits is 6048, while the sum is 28.

The square root of 20730664 is about 4553.0938931676. The cubic root of 20730664 is about 274.7078506232.

The spelling of 20730664 in words is "twenty million, seven hundred thirty thousand, six hundred sixty-four".