671156227681 has 4 divisors (see below), whose sum is σ = 671157903364. Its totient is φ = 671154552000.

The previous prime is 671156227603. The next prime is 671156227723. The reversal of 671156227681 is 186722651176.

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 305542512081 + 365613715600 = 552759^2 + 604660^2 .

It is a cyclic number.

It is not a de Polignac number, because 671156227681 - 2¹⁷ = 671156096609 is a prime.

It is a super-2 number, since 2×671156227681² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (671156227081) 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, 155581 + ... + 1168981.

It is an arithmetic number, because the mean of its divisors is an integer number (167789475841).

Almost surely, 2^671156227681 is an apocalyptic number.

It is an amenable number.

671156227681 is a deficient number, since it is larger than the sum of its proper divisors (1675683).

671156227681 is a wasteful number, since it uses less digits than its factorization.

671156227681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1675682.

The product of its digits is 1693440, while the sum is 52.

The spelling of 671156227681 in words is "six hundred seventy-one billion, one hundred fifty-six million, two hundred twenty-seven thousand, six hundred eighty-one".