1729128145 has 4 divisors (see below), whose sum is σ = 2074953780. Its totient is φ = 1383302512.

The previous prime is 1729128139. The next prime is 1729128173. The reversal of 1729128145 is 5418219271.

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 1081883664 + 647244481 = 32892^2 + 25441^2 .

It is a cyclic number.

It is not a de Polignac number, because 1729128145 - 2⁹ = 1729127633 is a prime.

It is a super-2 number, since 2×1729128145² = 5979768283662282050, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 1729128098 and 1729128107.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 172912810 + ... + 172912819.

It is an arithmetic number, because the mean of its divisors is an integer number (518738445).

Almost surely, 2^1729128145 is an apocalyptic number.

It is an amenable number.

1729128145 is a deficient number, since it is larger than the sum of its proper divisors (345825635).

1729128145 is an equidigital number, since it uses as much as digits as its factorization.

1729128145 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 345825634.

The product of its digits is 40320, while the sum is 40.

The square root of 1729128145 is about 41582.7866430330. The cubic root of 1729128145 is about 1200.2610878661.

The spelling of 1729128145 in words is "one billion, seven hundred twenty-nine million, one hundred twenty-eight thousand, one hundred forty-five".