981565663 has 4 divisors (see below), whose sum is σ = 1057070728. Its totient is φ = 906060600.

The previous prime is 981565649. The next prime is 981565691. The reversal of 981565663 is 366565189.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 366565189 = 197 ⋅1860737.

It is a cyclic number.

It is not a de Polignac number, because 981565663 - 2¹³ = 981557471 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 (981565633) 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, 37752513 + ... + 37752538.

It is an arithmetic number, because the mean of its divisors is an integer number (264267682).

Almost surely, 2^981565663 is an apocalyptic number.

981565663 is a deficient number, since it is larger than the sum of its proper divisors (75505065).

981565663 is a wasteful number, since it uses less digits than its factorization.

981565663 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 75505064.

The product of its digits is 1166400, while the sum is 49.

The square root of 981565663 is about 31329.9483402064. The cubic root of 981565663 is about 993.8170711795.

The spelling of 981565663 in words is "nine hundred eighty-one million, five hundred sixty-five thousand, six hundred sixty-three".