1608913440 has 72 divisors (see below), whose sum is σ = 5490422028. Its totient is φ = 429043200.

The previous prime is 1608913409. The next prime is 1608913441. The reversal of 1608913440 is 443198061.

1608913440 is a `hidden beast` number, since 1 + 608 + 9 + 1 + 3 + 4 + 40 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 1546376976 + 62536464 = 39324^2 + 7908^2 .

It is a tau number, because it is divible by the number of its divisors (72).

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 = 1608913395 and 1608913404.

It is not an unprimeable number, because it can be changed into a prime (1608913441) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 557211 + ... + 560090.

Almost surely, 2^1608913440 is an apocalyptic number.

1608913440 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1608913440 is an abundant number, since it is smaller than the sum of its proper divisors (3881508588).

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

1608913440 is a wasteful number, since it uses less digits than its factorization.

1608913440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1117322 (or 1117311 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 36.

The square root of 1608913440 is about 40111.2632560980. The cubic root of 1608913440 is about 1171.7749959249.

The spelling of 1608913440 in words is "one billion, six hundred eight million, nine hundred thirteen thousand, four hundred forty".