170130721 has 2 divisors, whose sum is σ = 170130722. Its totient is φ = 170130720.

The previous prime is 170130707. The next prime is 170130799. The reversal of 170130721 is 127031071.

170130721 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 138321121 + 31809600 = 11761^2 + 5640^2 .

It is a cyclic number.

It is not a de Polignac number, because 170130721 - 2⁷ = 170130593 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 170130692 and 170130701.

It is not a weakly prime, because it can be changed into another prime (170130221) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 85065360 + 85065361.

It is an arithmetic number, because the mean of its divisors is an integer number (85065361).

Almost surely, 2^170130721 is an apocalyptic number.

It is an amenable number.

170130721 is a deficient number, since it is larger than the sum of its proper divisors (1).

170130721 is an equidigital number, since it uses as much as digits as its factorization.

170130721 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 294, while the sum is 22.

The square root of 170130721 is about 13043.4167686232. The cubic root of 170130721 is about 554.1077794275.

Adding to 170130721 its reverse (127031071), we get a palindrome (297161792).

The spelling of 170130721 in words is "one hundred seventy million, one hundred thirty thousand, seven hundred twenty-one".