66377854321 has 3 divisors (see below), whose sum is σ = 66378111961. Its totient is φ = 66377596682.

The previous prime is 66377854307. The next prime is 66377854351. The reversal of 66377854321 is 12345877366.

The square root of 66377854321 is 257639.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is not a de Polignac number, because 66377854321 - 2⁹ = 66377853809 is a prime.

It is a super-3 number, since 3×66377854321³ (a number of 33 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66377854351) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 128820 + ... + 386458.

Almost surely, 2^66377854321 is an apocalyptic number.

66377854321 is the 257639-th square number.

66377854321 is the 128820-th centered octagonal number.

It is an amenable number.

66377854321 is a deficient number, since it is larger than the sum of its proper divisors (257640).

66377854321 is an frugal number, since it uses more digits than its factorization.

66377854321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 515278 (or 257639 counting only the distinct ones).

The product of its digits is 5080320, while the sum is 52.

The spelling of 66377854321 in words is "sixty-six billion, three hundred seventy-seven million, eight hundred fifty-four thousand, three hundred twenty-one".