961998181 has 2 divisors, whose sum is σ = 961998182. Its totient is φ = 961998180.

The previous prime is 961998173. The next prime is 961998197. The reversal of 961998181 is 181899169.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 695165956 + 266832225 = 26366^2 + 16335^2 .

It is a cyclic number.

It is not a de Polignac number, because 961998181 - 2³ = 961998173 is a prime.

It is a super-2 number, since 2×961998181² = 1850881000494617522, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (961998131) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 480999090 + 480999091.

It is an arithmetic number, because the mean of its divisors is an integer number (480999091).

Almost surely, 2^961998181 is an apocalyptic number.

It is an amenable number.

961998181 is a deficient number, since it is larger than the sum of its proper divisors (1).

961998181 is an equidigital number, since it uses as much as digits as its factorization.

961998181 is an evil number, because the sum of its binary digits is even.

The product of its digits is 279936, while the sum is 52.

The square root of 961998181 is about 31016.0955150709. The cubic root of 961998181 is about 987.1687912586.

The spelling of 961998181 in words is "nine hundred sixty-one million, nine hundred ninety-eight thousand, one hundred eighty-one".