206716624921 has 9 divisors (see below), whose sum is σ = 208163809749. Its totient is φ = 205279441500.

The previous prime is 206716624883. The next prime is 206716624967. The reversal of 206716624921 is 129426617602.

The square root of 206716624921 is 454661.

It is a perfect power (a square), and thus also a powerful number.

It is not a de Polignac number, because 206716624921 - 2¹⁵ = 206716592153 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (206716624421) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 68652306 + ... + 68655316.

Almost surely, 2^206716624921 is an apocalyptic number.

206716624921 is the 454661-st square number.

206716624921 is the 227331-st centered octagonal number.

It is an amenable number.

206716624921 is a deficient number, since it is larger than the sum of its proper divisors (1447184828).

206716624921 is an frugal number, since it uses more digits than its factorization.

206716624921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6324 (or 3162 counting only the distinct ones).

The product of its (nonzero) digits is 435456, while the sum is 46.

The spelling of 206716624921 in words is "two hundred six billion, seven hundred sixteen million, six hundred twenty-four thousand, nine hundred twenty-one".