1989170181 has 12 divisors (see below), whose sum is σ = 2876533452. Its totient is φ = 1324596096.

The previous prime is 1989170147. The next prime is 1989170219. The reversal of 1989170181 is 1810719891.

It can be written as a sum of positive squares in 2 ways, for example, as 969325956 + 1019844225 = 31134^2 + 31935^2 .

It is not a de Polignac number, because 1989170181 - 2¹³ = 1989161989 is a prime.

It is a super-2 number, since 2×1989170181² = 7913596017959145522, which contains 22 as substring.

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1989170681) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 118116 + ... + 133901.

It is an arithmetic number, because the mean of its divisors is an integer number (239711121).

Almost surely, 2^1989170181 is an apocalyptic number.

It is an amenable number.

1989170181 is a deficient number, since it is larger than the sum of its proper divisors (887363271).

1989170181 is a wasteful number, since it uses less digits than its factorization.

1989170181 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 252900 (or 252897 counting only the distinct ones).

The product of its (nonzero) digits is 36288, while the sum is 45.

The square root of 1989170181 is about 44600.1141366253. The cubic root of 1989170181 is about 1257.6428132975.

The spelling of 1989170181 in words is "one billion, nine hundred eighty-nine million, one hundred seventy thousand, one hundred eighty-one".