68815555 has 4 divisors (see below), whose sum is σ = 82578672. Its totient is φ = 55052440.

The previous prime is 68815553. The next prime is 68815561. The reversal of 68815555 is 55551886.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 68815555 - 2¹ = 68815553 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (68815553) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6881551 + ... + 6881560.

It is an arithmetic number, because the mean of its divisors is an integer number (20644668).

Almost surely, 2^68815555 is an apocalyptic number.

68815555 is a deficient number, since it is larger than the sum of its proper divisors (13763117).

68815555 is a wasteful number, since it uses less digits than its factorization.

68815555 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13763116.

The product of its digits is 240000, while the sum is 43.

The square root of 68815555 is about 8295.5141492255. The cubic root of 68815555 is about 409.7908014662.

The spelling of 68815555 in words is "sixty-eight million, eight hundred fifteen thousand, five hundred fifty-five".