1820724864 has 128 divisors (see below), whose sum is σ = 5718038400. Its totient is φ = 502247424.

The previous prime is 1820724821. The next prime is 1820724911. The reversal of 1820724864 is 4684270281.

It is a tau number, because it is divible by the number of its divisors (128).

It is a Harshad number since it is a multiple of its sum of digits (42).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 66274 + ... + 89630.

It is an arithmetic number, because the mean of its divisors is an integer number (44672175).

Almost surely, 2^1820724864 is an apocalyptic number.

1820724864 is a gapful number since it is divisible by the number (14) 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 1820724864, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2859019200).

1820724864 is an abundant number, since it is smaller than the sum of its proper divisors (3897313536).

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

1820724864 is a wasteful number, since it uses less digits than its factorization.

1820724864 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23410 (or 23398 counting only the distinct ones).

The product of its (nonzero) digits is 172032, while the sum is 42.

The square root of 1820724864 is about 42669.9527067936. The cubic root of 1820724864 is about 1221.0912175344.

It can be divided in two parts, 18207 and 24864, that added together give a triangular number (43071 = T₂₉₃).

The spelling of 1820724864 in words is "one billion, eight hundred twenty million, seven hundred twenty-four thousand, eight hundred sixty-four".