20655331 has 4 divisors (see below), whose sum is σ = 21321664. Its totient is φ = 19989000.

The previous prime is 20655329. The next prime is 20655367. The reversal of 20655331 is 13355602.

It is a happy number.

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 20655331 - 2¹ = 20655329 is a prime.

It is a super-2 number, since 2×20655331² = 853285397439122, 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 = 20655296 and 20655305.

It is not an unprimeable number, because it can be changed into a prime (20655301) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 333120 + ... + 333181.

It is an arithmetic number, because the mean of its divisors is an integer number (5330416).

Almost surely, 2^20655331 is an apocalyptic number.

20655331 is a deficient number, since it is larger than the sum of its proper divisors (666333).

20655331 is an equidigital number, since it uses as much as digits as its factorization.

20655331 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 666332.

The product of its (nonzero) digits is 2700, while the sum is 25.

The square root of 20655331 is about 4544.8136375433. The cubic root of 20655331 is about 274.3746938317.

It can be divided in two parts, 2065 and 5331, that added together give a square (7396 = 86²).

The spelling of 20655331 in words is "twenty million, six hundred fifty-five thousand, three hundred thirty-one".