20638907 has 8 divisors (see below), whose sum is σ = 20867184. Its totient is φ = 20412288.

The previous prime is 20638861. The next prime is 20638931. The reversal of 20638907 is 70983602.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20638907 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20638507) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 65783 + ... + 66095.

It is an arithmetic number, because the mean of its divisors is an integer number (2608398).

Almost surely, 2^20638907 is an apocalyptic number.

20638907 is a deficient number, since it is larger than the sum of its proper divisors (228277).

20638907 is a wasteful number, since it uses less digits than its factorization.

20638907 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 829.

The product of its (nonzero) digits is 18144, while the sum is 35.

The square root of 20638907 is about 4543.0063834426. The cubic root of 20638907 is about 274.3019519183.

The spelling of 20638907 in words is "twenty million, six hundred thirty-eight thousand, nine hundred seven".