1818521280 has 280 divisors, whose sum is σ = 6850977408. Its totient is φ = 456302592.

The previous prime is 1818521273. The next prime is 1818521311. The reversal of 1818521280 is 821258181.

It is a super-5 number, since 5×1818521280⁵ (a number of 47 digits) contains 55555 as substring.

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 39 ways as a sum of consecutive naturals, for example, 438577 + ... + 442703.

Almost surely, 2^1818521280 is an apocalyptic number.

1818521280 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 1818521280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3425488704).

1818521280 is an abundant number, since it is smaller than the sum of its proper divisors (5032456128).

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

1818521280 is a wasteful number, since it uses less digits than its factorization.

1818521280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4173 (or 4154 counting only the distinct ones).

The product of its (nonzero) digits is 10240, while the sum is 36.

The square root of 1818521280 is about 42644.1236279983. The cubic root of 1818521280 is about 1220.5983985510.

The spelling of 1818521280 in words is "one billion, eight hundred eighteen million, five hundred twenty-one thousand, two hundred eighty".