20201906 has 4 divisors (see below), whose sum is σ = 30302862. Its totient is φ = 10100952.

The previous prime is 20201897. The next prime is 20201911. The reversal of 20201906 is 60910202.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 60910202 = 2 ⋅30455101.

It can be written as a sum of positive squares in only one way, i.e., 19882681 + 319225 = 4459^2 + 565^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5050475 + ... + 5050478.

Almost surely, 2^20201906 is an apocalyptic number.

20201906 is a deficient number, since it is larger than the sum of its proper divisors (10100956).

20201906 is a wasteful number, since it uses less digits than its factorization.

20201906 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10100955.

The product of its (nonzero) digits is 216, while the sum is 20.

The square root of 20201906 is about 4494.6530455643. The cubic root of 20201906 is about 272.3521336769.

The spelling of 20201906 in words is "twenty million, two hundred one thousand, nine hundred six".