1561782768 has 80 divisors (see below), whose sum is σ = 4965682176. Its totient is φ = 411897600.

The previous prime is 1561782763. The next prime is 1561782773. The reversal of 1561782768 is 8672871651.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (1561782763) and next prime (1561782773).

It is a self number, because there is not a number n which added to its sum of digits gives 1561782768.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1561782763) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 174408 + ... + 183143.

Almost surely, 2^1561782768 is an apocalyptic number.

It is an amenable number.

1561782768 is an abundant number, since it is smaller than the sum of its proper divisors (3403899408).

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

1561782768 is a wasteful number, since it uses less digits than its factorization.

1561782768 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 357582 (or 357576 counting only the distinct ones).

The product of its digits is 1128960, while the sum is 51.

The square root of 1561782768 is about 39519.3973638263. The cubic root of 1561782768 is about 1160.2196294402.

The spelling of 1561782768 in words is "one billion, five hundred sixty-one million, seven hundred eighty-two thousand, seven hundred sixty-eight".