160919981 has 2 divisors, whose sum is σ = 160919982. Its totient is φ = 160919980.

The previous prime is 160919971. The next prime is 160919999. The reversal of 160919981 is 189919061.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 150454756 + 10465225 = 12266^2 + 3235^2 .

It is an emirp because it is prime and its reverse (189919061) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 160919981 - 2⁶ = 160919917 is a prime.

It is a super-2 number, since 2×160919981² = 51790480570080722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (160919971) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80459990 + 80459991.

It is an arithmetic number, because the mean of its divisors is an integer number (80459991).

Almost surely, 2^160919981 is an apocalyptic number.

It is an amenable number.

160919981 is a deficient number, since it is larger than the sum of its proper divisors (1).

160919981 is an equidigital number, since it uses as much as digits as its factorization.

160919981 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 34992, while the sum is 44.

The square root of 160919981 is about 12685.4239582286. The cubic root of 160919981 is about 543.9220406684.

The spelling of 160919981 in words is "one hundred sixty million, nine hundred nineteen thousand, nine hundred eighty-one".