66345155838 has 40 divisors (see below), whose sum is σ = 160097859768. Its totient is φ = 20413893456.

The previous prime is 66345155837. The next prime is 66345155861. The reversal of 66345155838 is 83855154366.

It is a happy number.

66345155838 is a `hidden beast` number, since 6 + 6 + 3 + 4 + 51 + 5 + 583 + 8 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66345155837) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 15749356 + ... + 15753567.

Almost surely, 2^66345155838 is an apocalyptic number.

66345155838 is an abundant number, since it is smaller than the sum of its proper divisors (93752703930).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

66345155838 is a wasteful number, since it uses less digits than its factorization.

66345155838 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31502950 (or 31502941 counting only the distinct ones).

The product of its digits is 10368000, while the sum is 54.

The spelling of 66345155838 in words is "sixty-six billion, three hundred forty-five million, one hundred fifty-five thousand, eight hundred thirty-eight".