671991783 has 16 divisors (see below), whose sum is σ = 909729792. Its totient is φ = 441140000.

The previous prime is 671991773. The next prime is 671991797. The reversal of 671991783 is 387199176.

It is a cyclic number.

It is not a de Polignac number, because 671991783 - 2⁸ = 671991527 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (671991703) 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, 243793 + ... + 246533.

It is an arithmetic number, because the mean of its divisors is an integer number (56858112).

Almost surely, 2^671991783 is an apocalyptic number.

671991783 is a deficient number, since it is larger than the sum of its proper divisors (237738009).

671991783 is a wasteful number, since it uses less digits than its factorization.

671991783 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3966.

The product of its digits is 571536, while the sum is 51.

The square root of 671991783 is about 25922.8043043186. The cubic root of 671991783 is about 875.9002578729.

The spelling of 671991783 in words is "six hundred seventy-one million, nine hundred ninety-one thousand, seven hundred eighty-three".