206521057671 has 4 divisors (see below), whose sum is σ = 275361410232. Its totient is φ = 137680705112.

The previous prime is 206521057667. The next prime is 206521057681. The reversal of 206521057671 is 176750125602.

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 206521057671 - 2² = 206521057667 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (206521057601) 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, 34420176276 + ... + 34420176281.

It is an arithmetic number, because the mean of its divisors is an integer number (68840352558).

Almost surely, 2^206521057671 is an apocalyptic number.

206521057671 is a deficient number, since it is larger than the sum of its proper divisors (68840352561).

206521057671 is an equidigital number, since it uses as much as digits as its factorization.

206521057671 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 68840352560.

The product of its (nonzero) digits is 176400, while the sum is 42.

The spelling of 206521057671 in words is "two hundred six billion, five hundred twenty-one million, fifty-seven thousand, six hundred seventy-one".