671129820 has 96 divisors (see below), whose sum is σ = 2138955840. Its totient is φ = 174597120.

The previous prime is 671129801. The next prime is 671129827. The reversal of 671129820 is 28921176.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (671129827) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 6984 + ... + 37296.

It is an arithmetic number, because the mean of its divisors is an integer number (22280790).

Almost surely, 2^671129820 is an apocalyptic number.

671129820 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 671129820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1069477920).

671129820 is an abundant number, since it is smaller than the sum of its proper divisors (1467826020).

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

671129820 is a wasteful number, since it uses less digits than its factorization.

671129820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30372 (or 30364 counting only the distinct ones).

The product of its (nonzero) digits is 12096, while the sum is 36.

The square root of 671129820 is about 25906.1733955442. The cubic root of 671129820 is about 875.5255922529.

The spelling of 671129820 in words is "six hundred seventy-one million, one hundred twenty-nine thousand, eight hundred twenty".