207308106721 has 9 divisors (see below), whose sum is σ = 220228253011. Its totient is φ = 195106227232.

The previous prime is 207308106673. The next prime is 207308106743. The reversal of 207308106721 is 127601803702.

The square root of 207308106721 is 455311.

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

It can be written as a sum of positive squares in only one way, i.e., 161399045025 + 45909061696 = 401745^2 + 214264^2 .

It is not a de Polignac number, because 207308106721 - 2¹¹ = 207308104673 is a prime.

It is a super-2 number, since 2×207308106721² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (207308106751) 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, 7726896 + ... + 7753678.

Almost surely, 2^207308106721 is an apocalyptic number.

207308106721 is the 455311-st square number.

207308106721 is the 227656-th centered octagonal number.

It is an amenable number.

207308106721 is a deficient number, since it is larger than the sum of its proper divisors (12920146290).

207308106721 is an frugal number, since it uses more digits than its factorization.

207308106721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53600 (or 26800 counting only the distinct ones).

The product of its (nonzero) digits is 28224, while the sum is 37.

The spelling of 207308106721 in words is "two hundred seven billion, three hundred eight million, one hundred six thousand, seven hundred twenty-one".