166313421 has 6 divisors (see below), whose sum is σ = 240230510. Its totient is φ = 110875608.

The previous prime is 166313383. The next prime is 166313423. The reversal of 166313421 is 124313661.

166313421 is a `hidden beast` number, since 1 + 6 + 631 + 3 + 4 + 21 = 666.

It can be written as a sum of positive squares in only one way, i.e., 152250921 + 14062500 = 12339^2 + 3750^2 .

It is not a de Polignac number, because 166313421 - 2²² = 162119117 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (166313423) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 9239626 + ... + 9239643.

Almost surely, 2^166313421 is an apocalyptic number.

It is an amenable number.

166313421 is a deficient number, since it is larger than the sum of its proper divisors (73917089).

166313421 is a wasteful number, since it uses less digits than its factorization.

166313421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18479275 (or 18479272 counting only the distinct ones).

The product of its digits is 2592, while the sum is 27.

The square root of 166313421 is about 12896.2560846162. The cubic root of 166313421 is about 549.9321359793.

The spelling of 166313421 in words is "one hundred sixty-six million, three hundred thirteen thousand, four hundred twenty-one".