1561390480 has 80 divisors (see below), whose sum is σ = 3929842224. Its totient is φ = 573511680.

The previous prime is 1561390477. The next prime is 1561390499. The reversal of 1561390480 is 840931651.

It can be written as a sum of positive squares in 8 ways, for example, as 115261696 + 1446128784 = 10736^2 + 38028^2 .

It is a tau number, because it is divible by the number of its divisors (80).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 201070 + ... + 208690.

Almost surely, 2^1561390480 is an apocalyptic number.

1561390480 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 1561390480, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1964921112).

1561390480 is an abundant number, since it is smaller than the sum of its proper divisors (2368451744).

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

1561390480 is a wasteful number, since it uses less digits than its factorization.

1561390480 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7844 (or 7838 counting only the distinct ones).

The product of its (nonzero) digits is 25920, while the sum is 37.

The square root of 1561390480 is about 39514.4338185428. The cubic root of 1561390480 is about 1160.1224801311.

The spelling of 1561390480 in words is "one billion, five hundred sixty-one million, three hundred ninety thousand, four hundred eighty".