166409553 has 4 divisors (see below), whose sum is σ = 221879408. Its totient is φ = 110939700.

The previous prime is 166409539. The next prime is 166409561. The reversal of 166409553 is 355904661.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 166409553 - 2⁶ = 166409489 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (166409533) 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, 27734923 + ... + 27734928.

It is an arithmetic number, because the mean of its divisors is an integer number (55469852).

Almost surely, 2^166409553 is an apocalyptic number.

It is an amenable number.

166409553 is a deficient number, since it is larger than the sum of its proper divisors (55469855).

166409553 is an equidigital number, since it uses as much as digits as its factorization.

166409553 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 55469854.

The product of its (nonzero) digits is 97200, while the sum is 39.

The square root of 166409553 is about 12899.9826744070. The cubic root of 166409553 is about 550.0380722956.

The spelling of 166409553 in words is "one hundred sixty-six million, four hundred nine thousand, five hundred fifty-three".