20656281 has 8 divisors (see below), whose sum is σ = 27609120. Its totient is φ = 13737152.

The previous prime is 20656253. The next prime is 20656291. The reversal of 20656281 is 18265602.

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

It is a cyclic number.

It is not a de Polignac number, because 20656281 - 2¹⁴ = 20639897 is a prime.

It is a super-2 number, since 2×20656281² = 853363889501922, which contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (20656201) 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, 6960 + ... + 9473.

It is an arithmetic number, because the mean of its divisors is an integer number (3451140).

Almost surely, 2^20656281 is an apocalyptic number.

It is an amenable number.

20656281 is a deficient number, since it is larger than the sum of its proper divisors (6952839).

20656281 is a wasteful number, since it uses less digits than its factorization.

20656281 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16855.

The product of its (nonzero) digits is 5760, while the sum is 30.

The square root of 20656281 is about 4544.9181510782. The cubic root of 20656281 is about 274.3789002028.

The spelling of 20656281 in words is "twenty million, six hundred fifty-six thousand, two hundred eighty-one".