20656231 has 4 divisors (see below), whose sum is σ = 21554352. Its totient is φ = 19758112.

The previous prime is 20656219. The next prime is 20656253. The reversal of 20656231 is 13265602.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 20656231 - 2¹³ = 20648039 is a prime.

It is a super-2 number, since 2×20656231² = 853359758250722, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20656196 and 20656205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20656201) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 449026 + ... + 449071.

It is an arithmetic number, because the mean of its divisors is an integer number (5388588).

Almost surely, 2^20656231 is an apocalyptic number.

20656231 is a deficient number, since it is larger than the sum of its proper divisors (898121).

20656231 is an equidigital number, since it uses as much as digits as its factorization.

20656231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 898120.

The product of its (nonzero) digits is 2160, while the sum is 25.

The square root of 20656231 is about 4544.9126504257. The cubic root of 20656231 is about 274.3786788181.

The spelling of 20656231 in words is "twenty million, six hundred fifty-six thousand, two hundred thirty-one".