1660944391 has 2 divisors, whose sum is σ = 1660944392. Its totient is φ = 1660944390.

The previous prime is 1660944367. The next prime is 1660944407. The reversal of 1660944391 is 1934490661.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1660944391 - 2²³ = 1652555783 is a prime.

It is a zygodrome in base 2.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1660944331) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 830472195 + 830472196.

It is an arithmetic number, because the mean of its divisors is an integer number (830472196).

Almost surely, 2^1660944391 is an apocalyptic number.

1660944391 is a deficient number, since it is larger than the sum of its proper divisors (1).

1660944391 is an equidigital number, since it uses as much as digits as its factorization.

1660944391 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 139968, while the sum is 43.

The square root of 1660944391 is about 40754.6855097668. The cubic root of 1660944391 is about 1184.2726440145.

The spelling of 1660944391 in words is "one billion, six hundred sixty million, nine hundred forty-four thousand, three hundred ninety-one".