1979916181 has 2 divisors, whose sum is σ = 1979916182. Its totient is φ = 1979916180.

The previous prime is 1979916151. The next prime is 1979916229. The reversal of 1979916181 is 1816199791.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1785062500 + 194853681 = 42250^2 + 13959^2 .

It is a cyclic number.

It is not a de Polignac number, because 1979916181 - 2¹³ = 1979907989 is a prime.

It is a super-2 number, since 2×1979916181² = 7840136167571249522, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1979916131) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 989958090 + 989958091.

It is an arithmetic number, because the mean of its divisors is an integer number (989958091).

Almost surely, 2^1979916181 is an apocalyptic number.

It is an amenable number.

1979916181 is a deficient number, since it is larger than the sum of its proper divisors (1).

1979916181 is an equidigital number, since it uses as much as digits as its factorization.

1979916181 is an evil number, because the sum of its binary digits is even.

The product of its digits is 244944, while the sum is 52.

The square root of 1979916181 is about 44496.2490666348. The cubic root of 1979916181 is about 1255.6895161809.

The spelling of 1979916181 in words is "one billion, nine hundred seventy-nine million, nine hundred sixteen thousand, one hundred eighty-one".