1660047391 has 2 divisors, whose sum is σ = 1660047392. Its totient is φ = 1660047390.

The previous prime is 1660047373. The next prime is 1660047407. The reversal of 1660047391 is 1937400661.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1660047391 - 2¹⁷ = 1659916319 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1660047391.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1660047371) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 830023695 + 830023696.

It is an arithmetic number, because the mean of its divisors is an integer number (830023696).

Almost surely, 2^1660047391 is an apocalyptic number.

1660047391 is a deficient number, since it is larger than the sum of its proper divisors (1).

1660047391 is an equidigital number, since it uses as much as digits as its factorization.

1660047391 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 27216, while the sum is 37.

The square root of 1660047391 is about 40743.6791539498. The cubic root of 1660047391 is about 1184.0594151517.

The spelling of 1660047391 in words is "one billion, six hundred sixty million, forty-seven thousand, three hundred ninety-one".