981365643 has 12 divisors (see below), whose sum is σ = 1420999320. Its totient is φ = 652641696.

The previous prime is 981365641. The next prime is 981365657. The reversal of 981365643 is 346563189.

981365643 is a `hidden beast` number, since 9 + 81 + 3 + 6 + 564 + 3 = 666.

It is not a de Polignac number, because 981365643 - 2¹ = 981365641 is a prime.

It is not an unprimeable number, because it can be changed into a prime (981365641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 129621 + ... + 136982.

It is an arithmetic number, because the mean of its divisors is an integer number (118416610).

Almost surely, 2^981365643 is an apocalyptic number.

981365643 is a deficient number, since it is larger than the sum of its proper divisors (439633677).

981365643 is a wasteful number, since it uses less digits than its factorization.

981365643 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 267018 (or 267015 counting only the distinct ones).

The product of its digits is 466560, while the sum is 45.

The square root of 981365643 is about 31326.7560242040. The cubic root of 981365643 is about 993.7495610773.

The spelling of 981365643 in words is "nine hundred eighty-one million, three hundred sixty-five thousand, six hundred forty-three".