20953656 has 144 divisors (see below), whose sum is σ = 64654200. Its totient is φ = 6110208.

The previous prime is 20953643. The next prime is 20953663. The reversal of 20953656 is 65635902.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 20953656.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 395326 + ... + 395378.

Almost surely, 2^20953656 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20953656, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32327100).

20953656 is an abundant number, since it is smaller than the sum of its proper divisors (43700544).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20953656 is a wasteful number, since it uses less digits than its factorization.

20953656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 118 (or 94 counting only the distinct ones).

The product of its (nonzero) digits is 48600, while the sum is 36.

The square root of 20953656 is about 4577.5163571526. The cubic root of 20953656 is about 275.6893164421.

It can be divided in two parts, 20953 and 656, that added together give a square (21609 = 147²).

The spelling of 20953656 in words is "twenty million, nine hundred fifty-three thousand, six hundred fifty-six".