189686981 has 6 divisors (see below), whose sum is σ = 208499046. Its totient is φ = 172442600.

The previous prime is 189686953. The next prime is 189687031.

189686981 is nontrivially palindromic in base 10.

189686981 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 184552225 + 5134756 = 13585^2 + 2266^2 .

It is not a de Polignac number, because 189686981 - 2¹⁰ = 189685957 is a prime.

It is a super-2 number, since 2×189686981² = 71962301521788722, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (189686281) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 783710 + ... + 783951.

It is an arithmetic number, because the mean of its divisors is an integer number (34749841).

Almost surely, 2^189686981 is an apocalyptic number.

189686981 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

189686981 is a deficient number, since it is larger than the sum of its proper divisors (18812065).

189686981 is a wasteful number, since it uses less digits than its factorization.

189686981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1567683 (or 1567672 counting only the distinct ones).

The product of its digits is 1492992, while the sum is 56.

The square root of 189686981 is about 13772.6896792166. The cubic root of 189686981 is about 574.5738301516.

The spelling of 189686981 in words is "one hundred eighty-nine million, six hundred eighty-six thousand, nine hundred eighty-one".