168991982 has 4 divisors (see below), whose sum is σ = 253487976. Its totient is φ = 84495990.

The previous prime is 168991973. The next prime is 168992027. The reversal of 168991982 is 289199861.

168991982 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 42247994 + ... + 42247997.

It is an arithmetic number, because the mean of its divisors is an integer number (63371994).

Almost surely, 2^168991982 is an apocalyptic number.

168991982 is a deficient number, since it is larger than the sum of its proper divisors (84495994).

168991982 is an equidigital number, since it uses as much as digits as its factorization.

168991982 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 84495993.

The product of its digits is 559872, while the sum is 53.

The square root of 168991982 is about 12999.6916117268. The cubic root of 168991982 is about 552.8687376958.

It can be divided in two parts, 16899 and 1982, that added together give a palindrome (18881).

The spelling of 168991982 in words is "one hundred sixty-eight million, nine hundred ninety-one thousand, nine hundred eighty-two".