1561787460 has 288 divisors, whose sum is σ = 5326339200. Its totient is φ = 378846720.

The previous prime is 1561787449. The next prime is 1561787503. The reversal of 1561787460 is 647871651.

1561787460 is a `hidden beast` number, since 1 + 561 + 7 + 87 + 4 + 6 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 8628570 + ... + 8628750.

Almost surely, 2^1561787460 is an apocalyptic number.

1561787460 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 1561787460, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2663169600).

1561787460 is an abundant number, since it is smaller than the sum of its proper divisors (3764551740).

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

1561787460 is a wasteful number, since it uses less digits than its factorization.

1561787460 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 276 (or 239 counting only the distinct ones).

The product of its (nonzero) digits is 282240, while the sum is 45.

The square root of 1561787460 is about 39519.4567270351. The cubic root of 1561787460 is about 1160.2207913058.

The spelling of 1561787460 in words is "one billion, five hundred sixty-one million, seven hundred eighty-seven thousand, four hundred sixty".