671606643 has 16 divisors (see below), whose sum is σ = 908819456. Its totient is φ = 441080640.

The previous prime is 671606633. The next prime is 671606657. The reversal of 671606643 is 346606176.

It is a happy number.

It is not a de Polignac number, because 671606643 - 2⁴ = 671606627 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (671606633) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 289458 + ... + 291768.

It is an arithmetic number, because the mean of its divisors is an integer number (56801216).

Almost surely, 2^671606643 is an apocalyptic number.

671606643 is a deficient number, since it is larger than the sum of its proper divisors (237212813).

671606643 is a wasteful number, since it uses less digits than its factorization.

671606643 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3714.

The product of its (nonzero) digits is 108864, while the sum is 39.

The square root of 671606643 is about 25915.3746451793. The cubic root of 671606643 is about 875.7328904030.

The spelling of 671606643 in words is "six hundred seventy-one million, six hundred six thousand, six hundred forty-three".