1985019181 has 2 divisors, whose sum is σ = 1985019182. Its totient is φ = 1985019180.

The previous prime is 1985019137. The next prime is 1985019221. The reversal of 1985019181 is 1819105891.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1547163556 + 437855625 = 39334^2 + 20925^2 .

It is a cyclic number.

It is not a de Polignac number, because 1985019181 - 2¹⁹ = 1984494893 is a prime.

It is a super-2 number, since 2×1985019181² = 7880602297875821522, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1985019121) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 992509590 + 992509591.

It is an arithmetic number, because the mean of its divisors is an integer number (992509591).

Almost surely, 2^1985019181 is an apocalyptic number.

It is an amenable number.

1985019181 is a deficient number, since it is larger than the sum of its proper divisors (1).

1985019181 is an equidigital number, since it uses as much as digits as its factorization.

1985019181 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 25920, while the sum is 43.

The square root of 1985019181 is about 44553.5540782102. The cubic root of 1985019181 is about 1256.7673877982.

The spelling of 1985019181 in words is "one billion, nine hundred eighty-five million, nineteen thousand, one hundred eighty-one".