159730721 has 2 divisors, whose sum is σ = 159730722. Its totient is φ = 159730720.

The previous prime is 159730679. The next prime is 159730729. The reversal of 159730721 is 127037951.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 136072225 + 23658496 = 11665^2 + 4864^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-159730721 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (159730729) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 79865360 + 79865361.

It is an arithmetic number, because the mean of its divisors is an integer number (79865361).

Almost surely, 2^159730721 is an apocalyptic number.

It is an amenable number.

159730721 is a deficient number, since it is larger than the sum of its proper divisors (1).

159730721 is an equidigital number, since it uses as much as digits as its factorization.

159730721 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 13230, while the sum is 35.

The square root of 159730721 is about 12638.4619713001. The cubic root of 159730721 is about 542.5787957779.

The spelling of 159730721 in words is "one hundred fifty-nine million, seven hundred thirty thousand, seven hundred twenty-one".