155055666561 has 8 divisors (see below), whose sum is σ = 206804455680. Its totient is φ = 103338660912.

The previous prime is 155055666547. The next prime is 155055666587. The reversal of 155055666561 is 165666550551.

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

It is not a de Polignac number, because 155055666561 - 2¹³ = 155055658369 is a prime.

It is a super-5 number, since 5×155055666561⁵ (a number of 57 digits) contains 55555 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (155055666541) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7934481 + ... + 7953998.

It is an arithmetic number, because the mean of its divisors is an integer number (25850556960).

Almost surely, 2^155055666561 is an apocalyptic number.

It is an amenable number.

155055666561 is a deficient number, since it is larger than the sum of its proper divisors (51748789119).

155055666561 is a wasteful number, since it uses less digits than its factorization.

155055666561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15891735.

The product of its (nonzero) digits is 4050000, while the sum is 51.

The spelling of 155055666561 in words is "one hundred fifty-five billion, fifty-five million, six hundred sixty-six thousand, five hundred sixty-one".