20506730 has 16 divisors (see below), whose sum is σ = 37034280. Its totient is φ = 8175552.

The previous prime is 20506729. The next prime is 20506747. The reversal of 20506730 is 3760502.

It can be written as a sum of positive squares in 4 ways, for example, as 5707321 + 14799409 = 2389^2 + 3847^2 .

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 20506696 and 20506705.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 65 + ... + 6404.

Almost surely, 2^20506730 is an apocalyptic number.

20506730 is a deficient number, since it is larger than the sum of its proper divisors (16527550).

20506730 is a wasteful number, since it uses less digits than its factorization.

20506730 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6793.

The product of its (nonzero) digits is 1260, while the sum is 23.

The square root of 20506730 is about 4528.4357122521. The cubic root of 20506730 is about 273.7151300775.

The spelling of 20506730 in words is "twenty million, five hundred six thousand, seven hundred thirty".