20966816 has 36 divisors (see below), whose sum is σ = 44709462. Its totient is φ = 9674496.

The previous prime is 20966809. The next prime is 20966821. The reversal of 20966816 is 61866902.

It can be written as a sum of positive squares in 3 ways, for example, as 7862416 + 13104400 = 2804^2 + 3620^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 20966816.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 3470 + ... + 7346.

Almost surely, 2^20966816 is an apocalyptic number.

20966816 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20966816, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22354731).

20966816 is an abundant number, since it is smaller than the sum of its proper divisors (23742646).

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

20966816 is a wasteful number, since it uses less digits than its factorization.

20966816 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3913 (or 3892 counting only the distinct ones).

The product of its (nonzero) digits is 31104, while the sum is 38.

The square root of 20966816 is about 4578.9535922523. The cubic root of 20966816 is about 275.7470201690.

The spelling of 20966816 in words is "twenty million, nine hundred sixty-six thousand, eight hundred sixteen".