155566 has 4 divisors (see below), whose sum is σ = 233352. Its totient is φ = 77782.

The previous prime is 155557. The next prime is 155569. The reversal of 155566 is 665551.

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

It is a plaindrome in base 10.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (155569) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38890 + ... + 38893.

It is an arithmetic number, because the mean of its divisors is an integer number (58338).

2¹⁵⁵⁵⁶⁶ is an apocalyptic number.

155566 is a deficient number, since it is larger than the sum of its proper divisors (77786).

155566 is an equidigital number, since it uses as much as digits as its factorization.

155566 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 77785.

The product of its digits is 4500, while the sum is 28.

The square root of 155566 is about 394.4185594011. The cubic root of 155566 is about 53.7821585095.

The spelling of 155566 in words is "one hundred fifty-five thousand, five hundred sixty-six".