309161889 has 9 divisors (see below), whose sum is σ = 446643379. Its totient is φ = 206072760.

The previous prime is 309161887. The next prime is 309161891. The reversal of 309161889 is 988161903.

The square root of 309161889 is 17583.

It is a perfect power (a square), and thus also a powerful number.

It is an interprime number because it is at equal distance from previous prime (309161887) and next prime (309161891).

It can be written as a sum of positive squares in only one way, i.e., 139641489 + 169520400 = 11817^2 + 13020^2 .

It is a tau number, because it is divible by the number of its divisors (9).

It is not a de Polignac number, because 309161889 - 2¹ = 309161887 is a prime.

It is a super-2 number, since 2×309161889² = 191162147220096642, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (309161887) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 49819 + ... + 55679.

Almost surely, 2^309161889 is an apocalyptic number.

309161889 is the 17583-rd square number.

309161889 is the 8792-nd centered octagonal number.

It is an amenable number.

309161889 is a deficient number, since it is larger than the sum of its proper divisors (137481490).

309161889 is an frugal number, since it uses more digits than its factorization.

309161889 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11728 (or 5864 counting only the distinct ones).

The product of its (nonzero) digits is 93312, while the sum is 45.

The cubic root of 309161889 is about 676.1794752675.

It can be divided in two parts, 3091 and 61889, that added together give a triangular number (64980 = T₃₆₀).

The spelling of 309161889 in words is "three hundred nine million, one hundred sixty-one thousand, eight hundred eighty-nine".