1820538720 has 768 divisors, whose sum is σ = 8575580160. Its totient is φ = 348364800.

The previous prime is 1820538701. The next prime is 1820538809. The reversal of 1820538720 is 278350281.

It is a super-2 number, since 2×1820538720² = 6628722462038476800, which contains 22 as substring.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 4324110 + ... + 4324530.

It is an arithmetic number, because the mean of its divisors is an integer number (11166120).

Almost surely, 2^1820538720 is an apocalyptic number.

1820538720 is a gapful number since it is divisible by the number (10) 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 1820538720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (4287790080).

1820538720 is an abundant number, since it is smaller than the sum of its proper divisors (6755041440).

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

1820538720 is a wasteful number, since it uses less digits than its factorization.

1820538720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 476 (or 462 counting only the distinct ones).

The product of its (nonzero) digits is 26880, while the sum is 36.

The square root of 1820538720 is about 42667.7714440302. The cubic root of 1820538720 is about 1221.0496028723.

The spelling of 1820538720 in words is "one billion, eight hundred twenty million, five hundred thirty-eight thousand, seven hundred twenty".