206398690 has 8 divisors (see below), whose sum is σ = 371517660. Its totient is φ = 82559472.

The previous prime is 206398679. The next prime is 206398721. The reversal of 206398690 is 96893602.

It can be written as a sum of positive squares in 2 ways, for example, as 193460281 + 12938409 = 13909^2 + 3597^2 .

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

It is a super-2 number, since 2×206398690² = 85200838467432200, which contains 22 as substring.

It is an unprimeable number.

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, 10319925 + ... + 10319944.

Almost surely, 2^206398690 is an apocalyptic number.

206398690 is a deficient number, since it is larger than the sum of its proper divisors (165118970).

206398690 is a wasteful number, since it uses less digits than its factorization.

206398690 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20639876.

The product of its (nonzero) digits is 139968, while the sum is 43.

The square root of 206398690 is about 14366.5824050120. The cubic root of 206398690 is about 590.9748224458.

The spelling of 206398690 in words is "two hundred six million, three hundred ninety-eight thousand, six hundred ninety".