20906121 has 8 divisors (see below), whose sum is σ = 28774144. Its totient is φ = 13487760.

The previous prime is 20906111. The next prime is 20906143. The reversal of 20906121 is 12160902.

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

It is not a de Polignac number, because 20906121 - 2⁷ = 20905993 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20906111) 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, 112306 + ... + 112491.

It is an arithmetic number, because the mean of its divisors is an integer number (3596768).

Almost surely, 2^20906121 is an apocalyptic number.

It is an amenable number.

20906121 is a deficient number, since it is larger than the sum of its proper divisors (7868023).

20906121 is a wasteful number, since it uses less digits than its factorization.

20906121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 224831.

The product of its (nonzero) digits is 216, while the sum is 21.

The square root of 20906121 is about 4572.3211829442. The cubic root of 20906121 is about 275.4806843704.

The spelling of 20906121 in words is "twenty million, nine hundred six thousand, one hundred twenty-one".