165981286 has 4 divisors (see below), whose sum is σ = 248971932. Its totient is φ = 82990642.

The previous prime is 165981269. The next prime is 165981287. The reversal of 165981286 is 682189561.

165981286 is digitally balanced in base 2 and base 3, because in such bases it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 682189561 = 13241 ⋅51521.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (165981287) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 41495320 + ... + 41495323.

It is an arithmetic number, because the mean of its divisors is an integer number (62242983).

Almost surely, 2^165981286 is an apocalyptic number.

165981286 is a deficient number, since it is larger than the sum of its proper divisors (82990646).

165981286 is an equidigital number, since it uses as much as digits as its factorization.

165981286 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 82990645.

The product of its digits is 207360, while the sum is 46.

The square root of 165981286 is about 12883.3724622088. The cubic root of 165981286 is about 549.5658127010.

The spelling of 165981286 in words is "one hundred sixty-five million, nine hundred eighty-one thousand, two hundred eighty-six".