205970689 has 4 divisors (see below), whose sum is σ = 206007124. Its totient is φ = 205934256.

The previous prime is 205970671. The next prime is 205970701. The reversal of 205970689 is 986079502.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 986079502 = 2 ⋅493039751.

It can be written as a sum of positive squares in 2 ways, for example, as 146603664 + 59367025 = 12108^2 + 7705^2 .

It is a cyclic number.

It is not a de Polignac number, because 205970689 - 2¹¹ = 205968641 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (205970629) 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, 7722 + ... + 21715.

It is an arithmetic number, because the mean of its divisors is an integer number (51501781).

Almost surely, 2^205970689 is an apocalyptic number.

It is an amenable number.

205970689 is a deficient number, since it is larger than the sum of its proper divisors (36435).

205970689 is an equidigital number, since it uses as much as digits as its factorization.

205970689 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36434.

The product of its (nonzero) digits is 272160, while the sum is 46.

The square root of 205970689 is about 14351.6789610136. The cubic root of 205970689 is about 590.5660458648.

The spelling of 205970689 in words is "two hundred five million, nine hundred seventy thousand, six hundred eighty-nine".