155705656665 has 32 divisors (see below), whose sum is σ = 270949222656. Its totient is φ = 75896121600.

The previous prime is 155705656577. The next prime is 155705656699. The reversal of 155705656665 is 566656507551.

It is a happy number.

It is not a de Polignac number, because 155705656665 - 2¹⁵ = 155705623897 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 3933229 + ... + 3972618.

It is an arithmetic number, because the mean of its divisors is an integer number (8467163208).

Almost surely, 2^155705656665 is an apocalyptic number.

155705656665 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

155705656665 is a deficient number, since it is larger than the sum of its proper divisors (115243565991).

155705656665 is a wasteful number, since it uses less digits than its factorization.

155705656665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7905969.

The product of its (nonzero) digits is 28350000, while the sum is 57.

The spelling of 155705656665 in words is "one hundred fifty-five billion, seven hundred five million, six hundred fifty-six thousand, six hundred sixty-five".