671515641 has 6 divisors (see below), whose sum is σ = 969967050. Its totient is φ = 447677088.

The previous prime is 671515609. The next prime is 671515643. The reversal of 671515641 is 146515176.

It is a happy number.

671515641 is a `hidden beast` number, since 6 + 7 + 1 + 5 + 1 + 5 + 641 = 666.

It can be written as a sum of positive squares in only one way, i.e., 643383225 + 28132416 = 25365^2 + 5304^2 .

It is not a de Polignac number, because 671515641 - 2⁵ = 671515609 is a prime.

It is a super-2 number, since 2×671515641² = 901866512215281762, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 671515596 and 671515605.

It is not an unprimeable number, because it can be changed into a prime (671515643) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 37306416 + ... + 37306433.

It is an arithmetic number, because the mean of its divisors is an integer number (161661175).

Almost surely, 2^671515641 is an apocalyptic number.

It is an amenable number.

671515641 is a deficient number, since it is larger than the sum of its proper divisors (298451409).

671515641 is a wasteful number, since it uses less digits than its factorization.

671515641 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 74612855 (or 74612852 counting only the distinct ones).

The product of its digits is 25200, while the sum is 36.

The square root of 671515641 is about 25913.6188325753. The cubic root of 671515641 is about 875.6933349852.

The spelling of 671515641 in words is "six hundred seventy-one million, five hundred fifteen thousand, six hundred forty-one".