981405668 has 6 divisors (see below), whose sum is σ = 1717459926. Its totient is φ = 490702832.

The previous prime is 981405661. The next prime is 981405673. The reversal of 981405668 is 866504189.

It can be written as a sum of positive squares in only one way, i.e., 980441344 + 964324 = 31312^2 + 982^2 .

It is not an unprimeable number, because it can be changed into a prime (981405661) 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 as a sum of consecutive naturals, namely, 122675705 + ... + 122675712.

It is an arithmetic number, because the mean of its divisors is an integer number (286243321).

Almost surely, 2^981405668 is an apocalyptic number.

It is an amenable number.

981405668 is a deficient number, since it is larger than the sum of its proper divisors (736054258).

981405668 is a wasteful number, since it uses less digits than its factorization.

981405668 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 245351421 (or 245351419 counting only the distinct ones).

The product of its (nonzero) digits is 414720, while the sum is 47.

The square root of 981405668 is about 31327.3948485986. The cubic root of 981405668 is about 993.7630709197.

The spelling of 981405668 in words is "nine hundred eighty-one million, four hundred five thousand, six hundred sixty-eight".