1161610605561 has 48 divisors (see below), whose sum is σ = 1849690168128. Its totient is φ = 646281417600.

The previous prime is 1161610605553. The next prime is 1161610605569. The reversal of 1161610605561 is 1655060161611.

It is an interprime number because it is at equal distance from previous prime (1161610605553) and next prime (1161610605569).

It is not a de Polignac number, because 1161610605561 - 2³ = 1161610605553 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1161610605569) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 451551 + ... + 1589691.

It is an arithmetic number, because the mean of its divisors is an integer number (38535211836).

Almost surely, 2^{1161610605561} is an apocalyptic number.

It is an amenable number.

1161610605561 is a deficient number, since it is larger than the sum of its proper divisors (688079562567).

1161610605561 is a wasteful number, since it uses less digits than its factorization.

1161610605561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1138342 (or 1138335 counting only the distinct ones).

The product of its (nonzero) digits is 32400, while the sum is 39.

The spelling of 1161610605561 in words is "one trillion, one hundred sixty-one billion, six hundred ten million, six hundred five thousand, five hundred sixty-one".