155555566 has 8 divisors (see below), whose sum is σ = 233399664. Its totient is φ = 77755680.

The previous prime is 155555549. The next prime is 155555573. The reversal of 155555566 is 665555551.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-2 number, since 2×155555566² = 48395068227160712, which contains 22 as substring.

It is a plaindrome in base 10.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 75 + ... + 17638.

It is an arithmetic number, because the mean of its divisors is an integer number (29174958).

Almost surely, 2^155555566 is an apocalyptic number.

155555566 is a deficient number, since it is larger than the sum of its proper divisors (77844098).

155555566 is a wasteful number, since it uses less digits than its factorization.

155555566 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22106.

The product of its digits is 562500, while the sum is 43.

The square root of 155555566 is about 12472.1917079557. The cubic root of 155555566 is about 537.8095607115.

It can be divided in two parts, 1555 and 55566, that added together give a square (57121 = 239²).

The spelling of 155555566 in words is "one hundred fifty-five million, five hundred fifty-five thousand, five hundred sixty-six".