206521210971 has 6 divisors (see below), whose sum is σ = 298308415860. Its totient is φ = 137680807308.

The previous prime is 206521210967. The next prime is 206521211011. The reversal of 206521210971 is 179012125602.

206521210971 is a `hidden beast` number, since 20 + 6 + 521 + 2 + 109 + 7 + 1 = 666.

206521210971 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 206521210971 - 2² = 206521210967 is a prime.

It is not an unprimeable number, because it can be changed into a prime (206521210901) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 11473400601 + ... + 11473400618.

It is an arithmetic number, because the mean of its divisors is an integer number (49718069310).

Almost surely, 2^206521210971 is an apocalyptic number.

206521210971 is a deficient number, since it is larger than the sum of its proper divisors (91787204889).

206521210971 is a wasteful number, since it uses less digits than its factorization.

206521210971 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22946801225 (or 22946801222 counting only the distinct ones).

The product of its (nonzero) digits is 15120, while the sum is 36.

The spelling of 206521210971 in words is "two hundred six billion, five hundred twenty-one million, two hundred ten thousand, nine hundred seventy-one".