20630906 has 4 divisors (see below), whose sum is σ = 30946362. Its totient is φ = 10315452.

The previous prime is 20630893. The next prime is 20630963. The reversal of 20630906 is 60903602.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 60903602 = 2 ⋅30451801.

It can be written as a sum of positive squares in only one way, i.e., 19882681 + 748225 = 4459^2 + 865^2 .

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5157725 + ... + 5157728.

Almost surely, 2^20630906 is an apocalyptic number.

20630906 is a deficient number, since it is larger than the sum of its proper divisors (10315456).

20630906 is a wasteful number, since it uses less digits than its factorization.

20630906 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10315455.

The product of its (nonzero) digits is 1944, while the sum is 26.

The square root of 20630906 is about 4542.1257138041. The cubic root of 20630906 is about 274.2665015013.

It can be divided in two parts, 206 and 30906, that multiplied together give a palindrome (6366636).

The spelling of 20630906 in words is "twenty million, six hundred thirty thousand, nine hundred six".