159721493 has 4 divisors (see below), whose sum is σ = 160532460. Its totient is φ = 158910528.

The previous prime is 159721481. The next prime is 159721537. The reversal of 159721493 is 394127951.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 96963409 + 62758084 = 9847^2 + 7922^2 .

It is a cyclic number.

It is not a de Polignac number, because 159721493 - 2¹⁴ = 159705109 is a prime.

It is a super-2 number, since 2×159721493² = 51021910652298098, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 159721493.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (159721693) 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, 405188 + ... + 405581.

It is an arithmetic number, because the mean of its divisors is an integer number (40133115).

Almost surely, 2^159721493 is an apocalyptic number.

It is an amenable number.

159721493 is a deficient number, since it is larger than the sum of its proper divisors (810967).

159721493 is an equidigital number, since it uses as much as digits as its factorization.

159721493 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 810966.

The product of its digits is 68040, while the sum is 41.

The square root of 159721493 is about 12638.0968899593. The cubic root of 159721493 is about 542.5683469143.

The spelling of 159721493 in words is "one hundred fifty-nine million, seven hundred twenty-one thousand, four hundred ninety-three".