20639006 has 4 divisors (see below), whose sum is σ = 30958512. Its totient is φ = 10319502.

The previous prime is 20638973. The next prime is 20639009. The reversal of 20639006 is 60093602.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 60093602 = 2 ⋅30046801.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20639009) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5159750 + ... + 5159753.

It is an arithmetic number, because the mean of its divisors is an integer number (7739628).

Almost surely, 2^20639006 is an apocalyptic number.

20639006 is a deficient number, since it is larger than the sum of its proper divisors (10319506).

20639006 is a wasteful number, since it uses less digits than its factorization.

20639006 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10319505.

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

The square root of 20639006 is about 4543.0172792980. The cubic root of 20639006 is about 274.3023905050.

The spelling of 20639006 in words is "twenty million, six hundred thirty-nine thousand, six".