161040561 has 32 divisors (see below), whose sum is σ = 249108480. Its totient is φ = 91512000.

The previous prime is 161040557. The next prime is 161040563. The reversal of 161040561 is 165040161.

It is not a de Polignac number, because 161040561 - 2² = 161040557 is a prime.

It is not an unprimeable number, because it can be changed into a prime (161040563) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 62056 + ... + 64598.

It is an arithmetic number, because the mean of its divisors is an integer number (7784640).

Almost surely, 2^161040561 is an apocalyptic number.

161040561 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

161040561 is a deficient number, since it is larger than the sum of its proper divisors (88067919).

161040561 is a wasteful number, since it uses less digits than its factorization.

161040561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2677.

The product of its (nonzero) digits is 720, while the sum is 24.

The square root of 161040561 is about 12690.1757671043. The cubic root of 161040561 is about 544.0578633394.

The spelling of 161040561 in words is "one hundred sixty-one million, forty thousand, five hundred sixty-one".