1161561616 has 10 divisors (see below), whose sum is σ = 2250525662. Its totient is φ = 580780800.

The previous prime is 1161561613. The next prime is 1161561649. The reversal of 1161561616 is 6161651611.

It can be written as a sum of positive squares in only one way, i.e., 645363216 + 516198400 = 25404^2 + 22720^2 .

It is not an unprimeable number, because it can be changed into a prime (1161561613) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36298785 + ... + 36298816.

Almost surely, 2^1161561616 is an apocalyptic number.

1161561616 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

1161561616 is a deficient number, since it is larger than the sum of its proper divisors (1088964046).

1161561616 is an equidigital number, since it uses as much as digits as its factorization.

1161561616 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 72597609 (or 72597603 counting only the distinct ones).

The product of its digits is 6480, while the sum is 34.

The square root of 1161561616 is about 34081.6903336674. The cubic root of 1161561616 is about 1051.1888623219.

The spelling of 1161561616 in words is "one billion, one hundred sixty-one million, five hundred sixty-one thousand, six hundred sixteen".