671909994 has 96 divisors (see below), whose sum is σ = 1753749504. Its totient is φ = 181764000.

The previous prime is 671909993. The next prime is 671909999. The reversal of 671909994 is 499909176.

It is a self number, because there is not a number n which added to its sum of digits gives 671909994.

It is not an unprimeable number, because it can be changed into a prime (671909993) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 297369 + ... + 299619.

It is an arithmetic number, because the mean of its divisors is an integer number (18268224).

Almost surely, 2^671909994 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 671909994, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (876874752).

671909994 is an abundant number, since it is smaller than the sum of its proper divisors (1081839510).

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

671909994 is a wasteful number, since it uses less digits than its factorization.

671909994 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2392 (or 2389 counting only the distinct ones).

The product of its (nonzero) digits is 1102248, while the sum is 54.

The square root of 671909994 is about 25921.2267070831. The cubic root of 671909994 is about 875.8647207752.

The spelling of 671909994 in words is "six hundred seventy-one million, nine hundred nine thousand, nine hundred ninety-four".