20216578 has 16 divisors (see below), whose sum is σ = 31306680. Its totient is φ = 9783936.

The previous prime is 20216569. The next prime is 20216591. The reversal of 20216578 is 87561202.

It can be written as a sum of positive squares in 4 ways, for example, as 20007729 + 208849 = 4473^2 + 457^2 .

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 in 7 ways as a sum of consecutive naturals, for example, 16350 + ... + 17542.

Almost surely, 2^20216578 is an apocalyptic number.

20216578 is a deficient number, since it is larger than the sum of its proper divisors (11090102).

20216578 is a wasteful number, since it uses less digits than its factorization.

20216578 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1461.

The product of its (nonzero) digits is 6720, while the sum is 31.

The square root of 20216578 is about 4496.2849109014. The cubic root of 20216578 is about 272.4180512776.

The spelling of 20216578 in words is "twenty million, two hundred sixteen thousand, five hundred seventy-eight".