671720790 has 64 divisors (see below), whose sum is σ = 1739102400. Its totient is φ = 165064704.

The previous prime is 671720747. The next prime is 671720809. The reversal of 671720790 is 97027176.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 314446 + ... + 316574.

It is an arithmetic number, because the mean of its divisors is an integer number (27173475).

Almost surely, 2^671720790 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 671720790, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (869551200).

671720790 is an abundant number, since it is smaller than the sum of its proper divisors (1067381610).

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

671720790 is a wasteful number, since it uses less digits than its factorization.

671720790 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2961.

The product of its (nonzero) digits is 37044, while the sum is 39.

The square root of 671720790 is about 25917.5768543280. The cubic root of 671720790 is about 875.7825010993.

The spelling of 671720790 in words is "six hundred seventy-one million, seven hundred twenty thousand, seven hundred ninety".