20178216 has 24 divisors (see below), whose sum is σ = 54649530. Its totient is φ = 6726048.

The previous prime is 20178187. The next prime is 20178239. The reversal of 20178216 is 61287102.

It can be written as a sum of positive squares in only one way, i.e., 13176900 + 7001316 = 3630^2 + 2646^2 .

It is a tau number, because it is divible by the number of its divisors (24).

It is a self number, because there is not a number n which added to its sum of digits gives 20178216.

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, 140055 + ... + 140198.

Almost surely, 2^20178216 is an apocalyptic number.

It is an amenable number.

20178216 is an abundant number, since it is smaller than the sum of its proper divisors (34471314).

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

20178216 is a wasteful number, since it uses less digits than its factorization.

20178216 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 280265 (or 280258 counting only the distinct ones).

The product of its (nonzero) digits is 1344, while the sum is 27.

The square root of 20178216 is about 4492.0169189352. The cubic root of 20178216 is about 272.2456330708.

The spelling of 20178216 in words is "twenty million, one hundred seventy-eight thousand, two hundred sixteen".