1691128039 has 4 divisors (see below), whose sum is σ = 1716368824. Its totient is φ = 1665887256.

The previous prime is 1691128007. The next prime is 1691128067. The reversal of 1691128039 is 9308211961.

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

It is a cyclic number.

It is not a de Polignac number, because 1691128039 - 2⁵ = 1691128007 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1691127992 and 1691128010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1691128139) 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, 12620292 + ... + 12620425.

It is an arithmetic number, because the mean of its divisors is an integer number (429092206).

Almost surely, 2^1691128039 is an apocalyptic number.

1691128039 is a deficient number, since it is larger than the sum of its proper divisors (25240785).

1691128039 is an equidigital number, since it uses as much as digits as its factorization.

1691128039 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25240784.

The product of its (nonzero) digits is 23328, while the sum is 40.

The square root of 1691128039 is about 41123.3271878626. The cubic root of 1691128039 is about 1191.4033860951.

The spelling of 1691128039 in words is "one billion, six hundred ninety-one million, one hundred twenty-eight thousand, thirty-nine".