80820720 has 320 divisors, whose sum is σ = 308551680. Its totient is φ = 19353600.

The previous prime is 80820697. The next prime is 80820721. The reversal of 80820720 is 2702808.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (80820721) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1138285 + ... + 1138355.

It is an arithmetic number, because the mean of its divisors is an integer number (964224).

Almost surely, 2^80820720 is an apocalyptic number.

80820720 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 80820720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (154275840).

80820720 is an abundant number, since it is smaller than the sum of its proper divisors (227730960).

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

80820720 is a wasteful number, since it uses less digits than its factorization.

80820720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 141 (or 129 counting only the distinct ones).

The product of its (nonzero) digits is 1792, while the sum is 27.

The square root of 80820720 is about 8990.0344826925. The cubic root of 80820720 is about 432.3554173854.

It can be divided in two parts, 808 and 20720, that added together give a triangular number (21528 = T₂₀₇).

The spelling of 80820720 in words is "eighty million, eight hundred twenty thousand, seven hundred twenty".