1659821663 has 2 divisors, whose sum is σ = 1659821664. Its totient is φ = 1659821662.

The previous prime is 1659821621. The next prime is 1659821671. The reversal of 1659821663 is 3661289561.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1659821663 - 2²² = 1655627359 is a prime.

It is a super-4 number, since 4×1659821663⁴ (a number of 38 digits) contains 4444 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1659821693) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 829910831 + 829910832.

It is an arithmetic number, because the mean of its divisors is an integer number (829910832).

Almost surely, 2^1659821663 is an apocalyptic number.

1659821663 is a deficient number, since it is larger than the sum of its proper divisors (1).

1659821663 is an equidigital number, since it uses as much as digits as its factorization.

1659821663 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 466560, while the sum is 47.

The square root of 1659821663 is about 40740.9089613867. The cubic root of 1659821663 is about 1184.0057444994.

The spelling of 1659821663 in words is "one billion, six hundred fifty-nine million, eight hundred twenty-one thousand, six hundred sixty-three".