123581655 has 24 divisors (see below), whose sum is σ = 221120640. Its totient is φ = 63783360.

The previous prime is 123581639. The next prime is 123581657. The reversal of 123581655 is 556185321.

It is a happy number.

123581655 is a `hidden beast` number, since 1 + 23 + 581 + 6 + 55 = 666.

It is not a de Polignac number, because 123581655 - 2⁴ = 123581639 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (123581657) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 42900 + ... + 45689.

It is an arithmetic number, because the mean of its divisors is an integer number (9213360).

Almost surely, 2^123581655 is an apocalyptic number.

123581655 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

123581655 is a deficient number, since it is larger than the sum of its proper divisors (97538985).

123581655 is a wasteful number, since it uses less digits than its factorization.

123581655 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 88631 (or 88628 counting only the distinct ones).

The product of its digits is 36000, while the sum is 36.

The square root of 123581655 is about 11116.7286105221. The cubic root of 123581655 is about 498.1016751803.

The spelling of 123581655 in words is "one hundred twenty-three million, five hundred eighty-one thousand, six hundred fifty-five".