1663754891 has 2 divisors, whose sum is σ = 1663754892. Its totient is φ = 1663754890.

The previous prime is 1663754863. The next prime is 1663754909. The reversal of 1663754891 is 1984573661.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1663754891 is a prime.

It is not a weakly prime, because it can be changed into another prime (1663754831) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 831877445 + 831877446.

It is an arithmetic number, because the mean of its divisors is an integer number (831877446).

Almost surely, 2^1663754891 is an apocalyptic number.

1663754891 is a deficient number, since it is larger than the sum of its proper divisors (1).

1663754891 is an equidigital number, since it uses as much as digits as its factorization.

1663754891 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1088640, while the sum is 50.

The square root of 1663754891 is about 40789.1516337371. The cubic root of 1663754891 is about 1184.9402406558.

The spelling of 1663754891 in words is "one billion, six hundred sixty-three million, seven hundred fifty-four thousand, eight hundred ninety-one".