166538247 has 4 divisors (see below), whose sum is σ = 222051000. Its totient is φ = 111025496.

The previous prime is 166538237. The next prime is 166538257. The reversal of 166538247 is 742835661.

166538247 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (166538237) and next prime (166538257).

It is a cyclic number.

It is not a de Polignac number, because 166538247 - 2²³ = 158149639 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 166538199 and 166538208.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (166538237) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 27756372 + ... + 27756377.

It is an arithmetic number, because the mean of its divisors is an integer number (55512750).

Almost surely, 2^166538247 is an apocalyptic number.

166538247 is a deficient number, since it is larger than the sum of its proper divisors (55512753).

166538247 is an equidigital number, since it uses as much as digits as its factorization.

166538247 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 55512752.

The product of its digits is 241920, while the sum is 42.

The square root of 166538247 is about 12904.9698566095. The cubic root of 166538247 is about 550.1798276986.

It can be divided in two parts, 1665 and 38247, that multiplied together give a triangular number (63681255 = T₁₁₂₈₅).

The spelling of 166538247 in words is "one hundred sixty-six million, five hundred thirty-eight thousand, two hundred forty-seven".