671236081920 has 216 divisors, whose sum is σ = 2376418140096. Its totient is φ = 174833455104.

The previous prime is 671236081907. The next prime is 671236081921. The reversal of 671236081920 is 29180632176.

671236081920 is a `hidden beast` number, since 6 + 7 + 1 + 2 + 3 + 608 + 19 + 20 = 666.

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

It is not an unprimeable number, because it can be changed into a prime (671236081921) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 182164 + ... + 1172883.

Almost surely, 2^671236081920 is an apocalyptic number.

671236081920 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 671236081920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1188209070048).

671236081920 is an abundant number, since it is smaller than the sum of its proper divisors (1705182058176).

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

671236081920 is a wasteful number, since it uses less digits than its factorization.

671236081920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1355117 (or 1355100 counting only the distinct ones).

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

The spelling of 671236081920 in words is "six hundred seventy-one billion, two hundred thirty-six million, eighty-one thousand, nine hundred twenty".