205620389 has 8 divisors (see below), whose sum is σ = 234463320. Its totient is φ = 178638336.

The previous prime is 205620379. The next prime is 205620407. The reversal of 205620389 is 983026502.

It can be written as a sum of positive squares in 4 ways, for example, as 26863489 + 178756900 = 5183^2 + 13370^2 .

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-205620389 is a prime.

It is a super-2 number, since 2×205620389² = 84559488745022642, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (205620329) 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, 464984 + ... + 465425.

It is an arithmetic number, because the mean of its divisors is an integer number (29307915).

Almost surely, 2^205620389 is an apocalyptic number.

It is an amenable number.

205620389 is a deficient number, since it is larger than the sum of its proper divisors (28842931).

205620389 is a wasteful number, since it uses less digits than its factorization.

205620389 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 930439.

The product of its (nonzero) digits is 25920, while the sum is 35.

The square root of 205620389 is about 14339.4696205962. The cubic root of 205620389 is about 590.2310585950.

The spelling of 205620389 in words is "two hundred five million, six hundred twenty thousand, three hundred eighty-nine".