919980161 has 2 divisors, whose sum is σ = 919980162. Its totient is φ = 919980160.

The previous prime is 919980037. The next prime is 919980163. The reversal of 919980161 is 161089919.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 600250000 + 319730161 = 24500^2 + 17881^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-919980161 is a prime.

Together with 919980163, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (919980163) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 459990080 + 459990081.

It is an arithmetic number, because the mean of its divisors is an integer number (459990081).

Almost surely, 2^919980161 is an apocalyptic number.

It is an amenable number.

919980161 is a deficient number, since it is larger than the sum of its proper divisors (1).

919980161 is an equidigital number, since it uses as much as digits as its factorization.

919980161 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 919980161 is about 30331.1747382128. The cubic root of 919980161 is about 972.5818351578.

The spelling of 919980161 in words is "nine hundred nineteen million, nine hundred eighty thousand, one hundred sixty-one".