671639040 has 400 divisors, whose sum is σ = 2495465280. Its totient is φ = 172523520.

The previous prime is 671639029. The next prime is 671639041. The reversal of 671639040 is 40936176.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 671638986 and 671639004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (671639041) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 8501721 + ... + 8501799.

Almost surely, 2^671639040 is an apocalyptic number.

671639040 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 671639040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1247732640).

671639040 is an abundant number, since it is smaller than the sum of its proper divisors (1823826240).

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

671639040 is an equidigital number, since it uses as much as digits as its factorization.

671639040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 155 (or 130 counting only the distinct ones).

The product of its (nonzero) digits is 27216, while the sum is 36.

The square root of 671639040 is about 25915.9996913104. Note that the first 3 decimals coincide. The cubic root of 671639040 is about 875.7469713945.

The spelling of 671639040 in words is "six hundred seventy-one million, six hundred thirty-nine thousand, forty".