161658 has 24 divisors (see below), whose sum is σ = 400608. Its totient is φ = 46152.

The previous prime is 161641. The next prime is 161659. The reversal of 161658 is 856161.

161658 is a `hidden beast` number, since 1 + 6 + 1 + 658 = 666.

It is a super-2 number, since 2×161658² = 52266617928, which contains 22 as substring.

It is an alternating number because its digits alternate between odd and even.

It is a plaindrome in base 16.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 161658.

It is not an unprimeable number, because it can be changed into a prime (161659) 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, 516 + ... + 767.

It is an arithmetic number, because the mean of its divisors is an integer number (16692).

2¹⁶¹⁶⁵⁸ is an apocalyptic number.

161658 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

161658 is an abundant number, since it is smaller than the sum of its proper divisors (238950).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

161658 is a wasteful number, since it uses less digits than its factorization.

161658 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1298 (or 1295 counting only the distinct ones).

The product of its digits is 1440, while the sum is 27.

The square root of 161658 is about 402.0671585693. The cubic root of 161658 is about 54.4752293234.

The spelling of 161658 in words is "one hundred sixty-one thousand, six hundred fifty-eight".