671820481 has 4 divisors (see below), whose sum is σ = 672002500. Its totient is φ = 671638464.

The previous prime is 671820419. The next prime is 671820497. The reversal of 671820481 is 184028176.

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 607178881 + 64641600 = 24641^2 + 8040^2 .

It is a cyclic number.

It is not a de Polignac number, because 671820481 - 2⁷ = 671820353 is a prime.

It is a super-2 number, since 2×671820481² = 902685517382142722, which contains 22 as substring.

It is the 25920-th Hogben number.

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 671820481.

It is not an unprimeable number, because it can be changed into a prime (671820181) by changing a digit.

It is a nontrivial repunit in base 25919.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 85356 + ... + 92893.

It is an arithmetic number, because the mean of its divisors is an integer number (168000625).

Almost surely, 2^671820481 is an apocalyptic number.

It is an amenable number.

671820481 is a deficient number, since it is larger than the sum of its proper divisors (182019).

671820481 is a wasteful number, since it uses less digits than its factorization.

671820481 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 182018.

The product of its (nonzero) digits is 21504, while the sum is 37.

The square root of 671820481 is about 25919.5000144679. The cubic root of 671820481 is about 875.8258243152.

The spelling of 671820481 in words is "six hundred seventy-one million, eight hundred twenty thousand, four hundred eighty-one".