671005561 has 8 divisors (see below), whose sum is σ = 681138920. Its totient is φ = 660897792.

The previous prime is 671005541. The next prime is 671005591. The reversal of 671005561 is 165500176.

It can be written as a sum of positive squares in 4 ways, for example, as 219188025 + 451817536 = 14805^2 + 21256^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 671005561 - 2¹⁵ = 670972793 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (671005541) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 50161 + ... + 62113.

It is an arithmetic number, because the mean of its divisors is an integer number (85142365).

Almost surely, 2^671005561 is an apocalyptic number.

It is an amenable number.

671005561 is a deficient number, since it is larger than the sum of its proper divisors (10133359).

671005561 is a wasteful number, since it uses less digits than its factorization.

671005561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12795.

The product of its (nonzero) digits is 6300, while the sum is 31.

The square root of 671005561 is about 25903.7750337668. The cubic root of 671005561 is about 875.4715546950.

The spelling of 671005561 in words is "six hundred seventy-one million, five thousand, five hundred sixty-one".