166556397 has 16 divisors (see below), whose sum is σ = 261988352. Its totient is φ = 92104560.

The previous prime is 166556389. The next prime is 166556399. The reversal of 166556397 is 793655661.

It is not a de Polignac number, because 166556397 - 2³ = 166556389 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 (166556399) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 127273 + ... + 128574.

It is an arithmetic number, because the mean of its divisors is an integer number (16374272).

Almost surely, 2^166556397 is an apocalyptic number.

It is an amenable number.

166556397 is a deficient number, since it is larger than the sum of its proper divisors (95431955).

166556397 is a wasteful number, since it uses less digits than its factorization.

166556397 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 255888.

The product of its digits is 1020600, while the sum is 48.

The square root of 166556397 is about 12905.6730549011. The cubic root of 166556397 is about 550.1998139006.

The spelling of 166556397 in words is "one hundred sixty-six million, five hundred fifty-six thousand, three hundred ninety-seven".