1561603408 has 60 divisors (see below), whose sum is σ = 3292843932. Its totient is φ = 716861440.

The previous prime is 1561603399. The next prime is 1561603409. The reversal of 1561603408 is 8043061651.

It is a happy number.

It can be written as a sum of positive squares in 6 ways, for example, as 10188864 + 1551414544 = 3192^2 + 39388^2 .

It is a Harshad number since it is a multiple of its sum of digits (34).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1561603409) by changing a digit.

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 11 ways as a sum of consecutive naturals, for example, 185466 + ... + 193702.

Almost surely, 2^1561603408 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1561603408, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1646421966).

1561603408 is an abundant number, since it is smaller than the sum of its proper divisors (1731240524).

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

1561603408 is a wasteful number, since it uses less digits than its factorization.

1561603408 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8320 (or 8297 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 34.

The square root of 1561603408 is about 39517.1280332972. The cubic root of 1561603408 is about 1160.1752133273.

The spelling of 1561603408 in words is "one billion, five hundred sixty-one million, six hundred three thousand, four hundred eight".