68691555 has 24 divisors (see below), whose sum is σ = 125333520. Its totient is φ = 34706880.

The previous prime is 68691541. The next prime is 68691563. The reversal of 68691555 is 55519686.

It is a happy number.

68691555 is a `hidden beast` number, since 6 + 8 + 6 + 91 + 555 = 666.

It is not a de Polignac number, because 68691555 - 2⁹ = 68691043 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 68691555.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 39316 + ... + 41025.

It is an arithmetic number, because the mean of its divisors is an integer number (5222230).

Almost surely, 2^68691555 is an apocalyptic number.

68691555 is a deficient number, since it is larger than the sum of its proper divisors (56641965).

68691555 is a wasteful number, since it uses less digits than its factorization.

68691555 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 80371 (or 80368 counting only the distinct ones).

The product of its digits is 324000, while the sum is 45.

The square root of 68691555 is about 8288.0368604393. The cubic root of 68691555 is about 409.5445169796.

The spelling of 68691555 in words is "sixty-eight million, six hundred ninety-one thousand, five hundred fifty-five".