1601531663 has 4 divisors (see below), whose sum is σ = 1602117000. Its totient is φ = 1600946328.

The previous prime is 1601531629. The next prime is 1601531671. The reversal of 1601531663 is 3661351061.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 3661351061 = 947 ⋅3866263.

It is a cyclic number.

It is not a de Polignac number, because 1601531663 - 2⁶ = 1601531599 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1601531683) 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, 288545 + ... + 294042.

It is an arithmetic number, because the mean of its divisors is an integer number (400529250).

Almost surely, 2^1601531663 is an apocalyptic number.

1601531663 is a deficient number, since it is larger than the sum of its proper divisors (585337).

1601531663 is an equidigital number, since it uses as much as digits as its factorization.

1601531663 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 585336.

The product of its (nonzero) digits is 9720, while the sum is 32.

The square root of 1601531663 is about 40019.1412076771. The cubic root of 1601531663 is about 1169.9801937378.

The spelling of 1601531663 in words is "one billion, six hundred one million, five hundred thirty-one thousand, six hundred sixty-three".