820472640 has 224 divisors, whose sum is σ = 2903402880. Its totient is φ = 194912256.

The previous prime is 820472633. The next prime is 820472671. The reversal of 820472640 is 46274028.

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, 360787 + ... + 363053.

It is an arithmetic number, because the mean of its divisors is an integer number (12961620).

Almost surely, 2^820472640 is an apocalyptic number.

820472640 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 820472640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1451701440).

820472640 is an abundant number, since it is smaller than the sum of its proper divisors (2082930240).

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

820472640 is a wasteful number, since it uses less digits than its factorization.

820472640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2329 (or 2319 counting only the distinct ones).

The product of its (nonzero) digits is 21504, while the sum is 33.

The square root of 820472640 is about 28643.8935900830. The cubic root of 820472640 is about 936.1699596400.

The spelling of 820472640 in words is "eight hundred twenty million, four hundred seventy-two thousand, six hundred forty".