1620289440 has 384 divisors, whose sum is σ = 7071805440. Its totient is φ = 336614400.

The previous prime is 1620289417. The next prime is 1620289457. The reversal of 1620289440 is 449820261.

1620289440 is a `hidden beast` number, since 1 + 6 + 202 + 8 + 9 + 440 = 666.

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

It is a junction number, because it is equal to n+sod(n) for n = 1620289395 and 1620289404.

It is an unprimeable number.

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, 330205 + ... + 335075.

It is an arithmetic number, because the mean of its divisors is an integer number (18416160).

Almost surely, 2^1620289440 is an apocalyptic number.

1620289440 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 1620289440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3535902720).

1620289440 is an abundant number, since it is smaller than the sum of its proper divisors (5451516000).

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

1620289440 is a wasteful number, since it uses less digits than its factorization.

1620289440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4913 (or 4899 counting only the distinct ones).

The product of its (nonzero) digits is 27648, while the sum is 36.

The square root of 1620289440 is about 40252.8190317150. The cubic root of 1620289440 is about 1174.5302338206.

The spelling of 1620289440 in words is "one billion, six hundred twenty million, two hundred eighty-nine thousand, four hundred forty".