20722664 has 16 divisors (see below), whose sum is σ = 39905700. Its totient is φ = 10081152.

The previous prime is 20722661. The next prime is 20722687. The reversal of 20722664 is 46622702.

It can be written as a sum of positive squares in 2 ways, for example, as 20702500 + 20164 = 4550^2 + 142^2 .

20722664 is a modest number, since divided by 2664 gives 2072 as remainder.

It is not an unprimeable number, because it can be changed into a prime (20722661) by changing a digit.

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, 34709 + ... + 35300.

Almost surely, 2^20722664 is an apocalyptic number.

It is an amenable number.

20722664 is a deficient number, since it is larger than the sum of its proper divisors (19183036).

20722664 is a wasteful number, since it uses less digits than its factorization.

20722664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 70052 (or 70048 counting only the distinct ones).

The product of its (nonzero) digits is 8064, while the sum is 29.

The square root of 20722664 is about 4552.2152848915. The cubic root of 20722664 is about 274.6725093279.

The spelling of 20722664 in words is "twenty million, seven hundred twenty-two thousand, six hundred sixty-four".