671689620 has 144 divisors (see below), whose sum is σ = 2335027968. Its totient is φ = 153100800.

The previous prime is 671689609. The next prime is 671689621. The reversal of 671689620 is 26986176.

671689620 is a `hidden beast` number, since 6 + 7 + 16 + 8 + 9 + 620 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (671689621) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 756817 + ... + 757703.

It is an arithmetic number, because the mean of its divisors is an integer number (16215472).

Almost surely, 2^671689620 is an apocalyptic number.

671689620 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 671689620, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1167513984).

671689620 is an abundant number, since it is smaller than the sum of its proper divisors (1663338348).

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

671689620 is a wasteful number, since it uses less digits than its factorization.

671689620 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1510 (or 1505 counting only the distinct ones).

The product of its (nonzero) digits is 217728, while the sum is 45.

The square root of 671689620 is about 25916.9755179882. The cubic root of 671689620 is about 875.7689545170.

The spelling of 671689620 in words is "six hundred seventy-one million, six hundred eighty-nine thousand, six hundred twenty".