20500778 has 8 divisors (see below), whose sum is σ = 31055940. Its totient is φ = 10148800.

The previous prime is 20500763. The next prime is 20500807. The reversal of 20500778 is 87700502.

It can be written as a sum of positive squares in 2 ways, for example, as 17497489 + 3003289 = 4183^2 + 1733^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 20500778.

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 3 ways as a sum of consecutive naturals, for example, 50543 + ... + 50946.

Almost surely, 2^20500778 is an apocalyptic number.

20500778 is a deficient number, since it is larger than the sum of its proper divisors (10555162).

20500778 is a wasteful number, since it uses less digits than its factorization.

20500778 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 101592.

The product of its (nonzero) digits is 3920, while the sum is 29.

The square root of 20500778 is about 4527.7784839809. The cubic root of 20500778 is about 273.6886459250.

The spelling of 20500778 in words is "twenty million, five hundred thousand, seven hundred seventy-eight".