820180640 has 192 divisors, whose sum is σ = 2163345408. Its totient is φ = 292454400.

The previous prime is 820180633. The next prime is 820180643. The reversal of 820180640 is 46081028.

It is not an unprimeable number, because it can be changed into a prime (820180643) 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, 5986652 + ... + 5986788.

It is an arithmetic number, because the mean of its divisors is an integer number (11267424).

Almost surely, 2^820180640 is an apocalyptic number.

820180640 is a gapful number since it is divisible by the number (80) 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 820180640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1081672704).

820180640 is an abundant number, since it is smaller than the sum of its proper divisors (1343164768).

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

820180640 is a wasteful number, since it uses less digits than its factorization.

820180640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 271 (or 263 counting only the distinct ones).

The product of its (nonzero) digits is 3072, while the sum is 29.

The square root of 820180640 is about 28638.7960640806. The cubic root of 820180640 is about 936.0588878625.

The spelling of 820180640 in words is "eight hundred twenty million, one hundred eighty thousand, six hundred forty".