72818820 has 144 divisors (see below), whose sum is σ = 238820400. Its totient is φ = 17891328.

The previous prime is 72818813. The next prime is 72818857. The reversal of 72818820 is 2881827.

It can be written as a sum of positive squares in 8 ways, for example, as 4359744 + 68459076 = 2088^2 + 8274^2 .

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

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 161956 + ... + 162404.

It is an arithmetic number, because the mean of its divisors is an integer number (1658475).

Almost surely, 2^72818820 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 72818820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (119410200).

72818820 is an abundant number, since it is smaller than the sum of its proper divisors (166001580).

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

72818820 is a wasteful number, since it uses less digits than its factorization.

72818820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 534 (or 529 counting only the distinct ones).

The product of its (nonzero) digits is 14336, while the sum is 36.

The square root of 72818820 is about 8533.3944008232. The cubic root of 72818820 is about 417.5878739818.

The spelling of 72818820 in words is "seventy-two million, eight hundred eighteen thousand, eight hundred twenty".