671856642 has 24 divisors (see below), whose sum is σ = 1468576044. Its totient is φ = 221969664.

The previous prime is 671856641. The next prime is 671856733. The reversal of 671856642 is 246658176.

It can be written as a sum of positive squares in 2 ways, for example, as 597362481 + 74494161 = 24441^2 + 8631^2 .

It is not an unprimeable number, because it can be changed into a prime (671856641) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 163123 + ... + 167190.

Almost surely, 2^671856642 is an apocalyptic number.

671856642 is an abundant number, since it is smaller than the sum of its proper divisors (796719402).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

671856642 is a wasteful number, since it uses less digits than its factorization.

671856642 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 330434 (or 330431 counting only the distinct ones).

The product of its digits is 483840, while the sum is 45.

The square root of 671856642 is about 25920.1975686915. The cubic root of 671856642 is about 875.8415379224.

The spelling of 671856642 in words is "six hundred seventy-one million, eight hundred fifty-six thousand, six hundred forty-two".