66812155 has 8 divisors (see below), whose sum is σ = 81273312. Its totient is φ = 52717248.

The previous prime is 66812149. The next prime is 66812167. The reversal of 66812155 is 55121866.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 66812155 - 2³ = 66812147 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 66812155.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 91159 + ... + 91888.

It is an arithmetic number, because the mean of its divisors is an integer number (10159164).

Almost surely, 2^66812155 is an apocalyptic number.

66812155 is a deficient number, since it is larger than the sum of its proper divisors (14461157).

66812155 is a wasteful number, since it uses less digits than its factorization.

66812155 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 183125.

The product of its digits is 14400, while the sum is 34.

The square root of 66812155 is about 8173.8702583293. The cubic root of 66812155 is about 405.7748818733.

It can be divided in two parts, 6681 and 2155, that added together give a square (8836 = 94²).

The spelling of 66812155 in words is "sixty-six million, eight hundred twelve thousand, one hundred fifty-five".