168538401 has 40 divisors (see below), whose sum is σ = 262681320. Its totient is φ = 107557632.

The previous prime is 168538387. The next prime is 168538507. The reversal of 168538401 is 104835861.

It can be written as a sum of positive squares in 4 ways, for example, as 39125025 + 129413376 = 6255^2 + 11376^2 .

It is not a de Polignac number, because 168538401 - 2¹¹ = 168536353 is a prime.

It is a super-2 number, since 2×168538401² = 56810385223273602, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (168531401) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 368565 + ... + 369021.

It is an arithmetic number, because the mean of its divisors is an integer number (6567033).

Almost surely, 2^168538401 is an apocalyptic number.

It is an amenable number.

168538401 is a deficient number, since it is larger than the sum of its proper divisors (94142919).

168538401 is a wasteful number, since it uses less digits than its factorization.

168538401 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 655 (or 646 counting only the distinct ones).

The product of its (nonzero) digits is 23040, while the sum is 36.

The square root of 168538401 is about 12982.2340527353. The cubic root of 168538401 is about 552.3736541489.

The spelling of 168538401 in words is "one hundred sixty-eight million, five hundred thirty-eight thousand, four hundred one".