162181261 has 12 divisors (see below), whose sum is σ = 178817436. Its totient is φ = 146981120.

The previous prime is 162181259. The next prime is 162181319.

162181261 is nontrivially palindromic in base 10.

It can be written as a sum of positive squares in 2 ways, for example, as 24940036 + 137241225 = 4994^2 + 11715^2 .

It is not a de Polignac number, because 162181261 - 2¹ = 162181259 is a prime.

It is a super-2 number, since 2×162181261² = 52605522839100242, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (162181231) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 40815 + ... + 44611.

It is an arithmetic number, because the mean of its divisors is an integer number (14901453).

Almost surely, 2^162181261 is an apocalyptic number.

162181261 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

162181261 is a deficient number, since it is larger than the sum of its proper divisors (16636175).

162181261 is a wasteful number, since it uses less digits than its factorization.

162181261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4172 (or 4161 counting only the distinct ones).

The product of its digits is 1152, while the sum is 28.

The square root of 162181261 is about 12735.0406752393. The cubic root of 162181261 is about 545.3394187925.

The spelling of 162181261 in words is "one hundred sixty-two million, one hundred eighty-one thousand, two hundred sixty-one".