66855321157 has 4 divisors (see below), whose sum is σ = 66902771340. Its totient is φ = 66807870976.

The previous prime is 66855321119. The next prime is 66855321161. The reversal of 66855321157 is 75112355866.

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

It can be written as a sum of positive squares in 2 ways, for example, as 26660684961 + 40194636196 = 163281^2 + 200486^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66855321157 is a prime.

It is a super-2 number, since 2×66855321157² (a number of 22 digits) contains 22 as substring.

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 66855321157.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66855301157) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 23722978 + ... + 23725795.

It is an arithmetic number, because the mean of its divisors is an integer number (16725692835).

Almost surely, 2^66855321157 is an apocalyptic number.

It is an amenable number.

66855321157 is a deficient number, since it is larger than the sum of its proper divisors (47450183).

66855321157 is a wasteful number, since it uses less digits than its factorization.

66855321157 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 47450182.

The product of its digits is 1512000, while the sum is 49.

The spelling of 66855321157 in words is "sixty-six billion, eight hundred fifty-five million, three hundred twenty-one thousand, one hundred fifty-seven".