207313721 has 4 divisors (see below), whose sum is σ = 214462500. Its totient is φ = 200164944.

The previous prime is 207313643. The next prime is 207313739. The reversal of 207313721 is 127313702.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 127313702 = 2 ⋅63656851.

It can be written as a sum of positive squares in 2 ways, for example, as 101223721 + 106090000 = 10061^2 + 10300^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-207313721 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (207313751) 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, 3574346 + ... + 3574403.

It is an arithmetic number, because the mean of its divisors is an integer number (53615625).

Almost surely, 2^207313721 is an apocalyptic number.

It is an amenable number.

207313721 is a deficient number, since it is larger than the sum of its proper divisors (7148779).

207313721 is an equidigital number, since it uses as much as digits as its factorization.

207313721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7148778.

The product of its (nonzero) digits is 1764, while the sum is 26.

The square root of 207313721 is about 14398.3930006095. The cubic root of 207313721 is about 591.8468614502.

The spelling of 207313721 in words is "two hundred seven million, three hundred thirteen thousand, seven hundred twenty-one".